[The Wyrm Ouroboros]

I'm not sure that this is really helping.
So for 1-pass-guys this doesn't change anything concerning actual rules.
And if one guy doesn't move in IP 1 and IP 2 and then tries to rush in IP 3 using 4 MP, he couldn't move at all in the next turn, if he only get's 2 passes, aside from spending complex actions to sprint.

So your system doesn't prevent teleport-moves and can also be abused in one direction or the other. I wouldn't recommend such a change.

Of course nothing changes for the Mook.  Otherwise, you are incorrect, sir; perhaps you did not read my latest.  Sammy Lightning would regenerate all 4 points prior to his second and last initiative pass, thus enabling him to move 4 points within the combat turn, since for him - this time - Pass 1 consists of the same amount of time taken up by Passes 1 and 2 in the previous Turn, and Pass 2 consists of what was Passes 3 and 4 from last Turn.

The move-point system does prevent 'teleport-moves', and with the 'you regen what you used last Turn on this Phase' regeneration method, it restricts you from moving more than 4x Agility in any one rolling Combat Turn, so it can't really be abused.  With this single change, it prevents abuse in every direction, and so it works for me - which was my goal.

Why don't we just take the AGI x 4 for running rate per turn und AGI x 2 for walking and then divide the movement rates per pass according to the highest number of passes present in the encounter?
This prevents Joe McSlow to teleport-run in his only pass like in SR4, but still allows high-Agility characters to get some mileage out of their investment, despite weakening melee in the process. It wouldn't prevent you from calculating movement rates, but having at least one participant to get 31 initiative actually makes it really easy.
In the end it would prevent more weird cases, so that the effort should pay off.

Do what you like.  But Joe McSlow needs to always be able to run (4xAGI) per Turn.

[Lucean]

If you regenerate everything from IP3 when not getting a third pass in turn 2, then you get to do a teleport move by doing a maximum run on IP3 in turn 1 and a new maximum run on IP1.

But well, as long as you know how you meant to play it ... maybe I'm just not getting at which point of your later comments you are replacing or adding to your previous house rule.

@Erling
1) But then the whole combat turn takes 3 seconds, and you are allowed to move AGI x 4 meters per 3 seconds without sprinting. You'd have to split the turn into more tiny fractions. And you don't want to do that.
2) If you lose initiative, then you did something which could be interpreted as losing momentum or that others did to you. Might be problematic sometimes, yes. But I'd still prefer it to a system where an increased reaction allows you to walk faster (more passes -> more movement points).

[The Wyrm Ouroboros]

If you regenerate everything from IP3 when not getting a third pass in turn 2, then you get to do a teleport move by doing a maximum run on IP3 in turn 1 and a new maximum run on IP1.

But well, as long as you know how you meant to play it ... maybe I'm just not getting at which point of your later comments you are replacing or adding to your previous house rule.

Yeah, you're completely not understanding, so let's review.

Normal Sammy Lightning:
Turn 1, rolls a 32 for 4 IPs:

• IP1: No Move.
• IP2: No Move.
• IP3: Move 4 MPs. (Running!)
• IP4: No Move; still receives Running penalties.

Turn 2, rolls a 32 for 4 IPs:

• IP1: No Move; as did not move in T1/IP1, regenerates nothing.  Since he does not have 2+ MPs, takes Running penalties.
• IP2: No Move; as did not move in T1/IP2, regenerates nothing.  Since he does not have 2+ MPs, takes Running penalties.
• IP3: Regenerates the 4 MPs used in T1/IP3.  Is no longer considered Running unless he moves 3+ MPs.
• IP4: etc.

Sammy 'Lead Magnet' Lightning:
Turn 1, rolls a 32 for 4 IPs:

• IP1: No Move.  Represents seconds 0.00-0.75.
• IP2: No Move.  Represents seconds 0.76-1.50.
• IP3: Move 4 MPs. (Running!)  Represents seconds 1.51-2.25.
• IP4: No Move; still receives Running penalties.  Gets shot to hell, taking 9 boxes Physical, 9 boxes Stun; total penalties of -6.  Represents seconds 2.26-3.00.

Turn 2, rolls crappy to boot, getting 24, but with -6 is an 18 for 2 IPs.

• IP1: No Move; represents seconds 0.00-1.50, equivalent to T1/IP1 and T1/IP2. As he did not move in either of those IPs, regenerates nothing.  Since he does not have 2+ MPs, takes Running penalties.  Somehow manages not to get shot up further.
• IP2: Represents seconds 1.51-3.00, equivalent to T1/IP3 and T1/IP4.  Because he used 4 MPs during those two IPs of T1, he regenerates those 4 IPs.  Unless he moves, he no longer takes Running penalties - unless he moves 3+ MPs worth right now.  Which might not be smart, considering the last time he ran out from under cover.

Initiative Passes are not, after all, set in stone - the entire Turn represents 3 seconds for everyone, no matter how many IPs anyone or everyone gets.  Oh, you can use a more accurate representation of 'Sammy Lightning' against Mook McSlowpoke, and Sammy would get 3 IPs before Mook moves once - and one after Mook goes, too - but that can become boring for the McSlowpokes around your table as Sammy cleans up the opposition before they can even draw their weapon, so the baseline rules do it in such a way as to let everyone get into some blasting.

As I've said, this method isn't for everyone - but the core limitation is '4x Agility per Combat Turn'.  I've simply enabled you to keep that limitation, 'Combat Turn', aka 3 seconds, as a rolling limitation (4x Agility during ANY 3 seconds) instead of a static one.  It's the static one that enables so-called 'teleport attacks'.
On a seperate note - a Postive Quality I created for 3rd, and have carried along through 4th and into 5th:

Fleet of Foot
Cost: 10 Karma.
This character is exceptionally fast on his feet. He receives +2 to his Agility for determining walk and run rates, and +1m per hit when Sprinting.

As a note, it is estimated that the human body's true maximum sprint speed is approximately 40mph - or 65 kph.  A person with AGI 9, Fleet of Foot, and 3 hits on a Sprint test could hit that ... or without Fleet of Foot, AGI 11 and 5 successes on the Sprint test.

Further, humans don't have three speeds, 'walk, run, sprint'; we have, loosely, four - insert 'jog' or 'trot' between 'walk' and 'run'.  Jogging is equivalent to 3x your AGI, and can be continued for 2-3 times as long as Running.  Running endurance lasts ... okay, that one's a little confusing, because it says different things in different places (see my submitted errata), but it essentially should be 10 Turns x (Running + Body), with 20 Turns being 1 minute.  Double that for jogging - 20 Turns x (Running + Body).  If your Body + Running is, for example, a total of 6, then you could Run for 3 minutes, but jog for 6, until needing to resist Fatigue damage every 10 (Running) or 20 (Jogging) Turns.

Jogging will get you there slower, but you can go further without tiring ...

[Erling]

@Erling
1) But then the whole combat turn takes 3 seconds, and you are allowed to move AGI x 4 meters per 3 seconds without sprinting. You'd have to split the turn into more tiny fractions. And you don't want to do that.
2) If you lose initiative, then you did something which could be interpreted as losing momentum or that others did to you. Might be problematic sometimes, yes. But I'd still prefer it to a system where an increased reaction allows you to walk faster (more passes -> more movement points).

1) Why not? At least that will reliably prevent teleport charges. Overall movement rate is not affected though. 3-IP system just makes movement more phased.
2) Losing Initiative affecting your own movement would make sense. But changing  whole encounter's "movement per IP" degree is a different story. And 3-IPs system doesn't make movement speed dependent on Initiative. Movement speed is determined with Agility only, and Initiative has nothing to do with that as everyone has the same number of IPs to move.

On the other hand, one can simply ignore reducing Initiative Score for the purpose of movement calculation. So if at the beginning of the Combat Turn highest Initiative Score is 11, movement rate will be evenly divided between 2 IPs notwithstanding how dramatically Initiative Score will change after.
"Teleport charge" is still possible, but it's a really rare case when highest Initiative Score is less than 11 at the beginning of the Combat Turn. So normally even a character with Agi 5 will be able to run up to 10 meters per IP (5 x 4 / 2), which is not actually a "teleport". It's still much, and Agi 6+ character will be able to charge from fragging long distances, but at least there's ANY limitation.
Hmm, I'v just re-read my SR3 core rulebook. That's actually what was suggester by SR3 rules (though I'm not sure about Initiative Score decrease and its effect on movement). Also movement rate was calculated in another way, so sammy with Quickness 5(7) could move about 11 meters per IP (with overall 2 IPs in Combat Turn). Damn, I should borrow rules from SR3.

Personally I would prefer "standardized 3 IP" system, but SR3 got it right too.