All these items are different in the ways they affect balance and some I have issues with while others I'm more okay with.
Form fitting body armor is merely armor inflation. Everyone wears the heaviest version their GM lets them get away with (typically full or half) and gets +2 or +3 ballistic and +1 impact over their normal encumbrance. If NPCs don't wear it, it's one of the small advantages PCs have over their foes. If you remove it, the game becomes slightly more deadly especially to low body types. +3 armor is big when you're otherwise rolling only 9 dice to soak damage; it matters far less when you're already rolling 18 dice.
The Securetech PPP system is different. Since it doesn't increase your armor encumbrance limit, it merely makes it easier to reach your cap. Unless you have 6+ body, it's pretty easy to reach or at least nearly reach your cap in street walkable style (typically X piece of armor + helmet will hit your cap with maybe gel packs too). Its biggest advantage is that it makes it easy to "equalize" your ballistic and impact armors due to the fact the PPP system is very weighted towards impact while the vast majority of armors are weighted towards ballistic. For that reason, nearly everyone will use at least some PPP system to equalize your ballistic and impact. So I'm fairly okay with the PPP system. Then again, I think ballistic and impact armor should just be combined into "armor."
Together, the armors do make life better for both low and high body types. Low body types (body 3 or less) get a noteworthy increase in protection. High body types (body 6+) do well since it's easier for them to reach their armor encumbrance. Since the main reason body makes you tough is because you wear more armor, it makes it possible to buy more armor.
Cyberlimbs are interesting. I will admit I like that cyberlimbs are a worthwhile option for once. In prior editions, they were mostly worthless except for the wealthiest of runners or the odd cyberdeck hiding spot. So while I can find fault with the implementation, I'm happy with at least some of the outcome.
Cyberlimb armor is really good. While it eats capacity like there's no tomorrow, it vastly increases survivability. It's one of the few advantages mundanes have over mages. A mundane can typically get a limb or two and get +6 armor over his mage brother. Since mages have trouble equaling this (the armor spell sucks), it makes a mundane notably tougher than a mage.
Sure, a mage can still stunbolt the mundane just as easily as before, but since most damage to PCs is caused by dudes with guns, it's a worthwhile difference. It's enough of one, it makes cyberlimbs tempting for some mages (typically logic sorts who want to get a cerebral booster too). It's not enough that every mage wants one, but allows cybermages to not cry themselves to sleep. That's a pretty good sweet spot for balance (not everyone needs it nor does everyone avoid it) especially for SR standards.
However, one issue is cyberleporsy. Just cut off your hands and feet and replace them with cyberhands and feet and armor 2 (bulky and armor 3 if the GM doesn't slap you). +8 armor for 1 essence and ~22000Y is a great deal. I must admit I'm not too crazy about this either. But getting +3 armor with a full cyberlimb isn't too bad and spamming that is fairly hard to do without some sort of cost.
Cyberlimb armor however does regulate bone lacing to a small niche (adepts and other punchy dudes) and destroys dermal plating and orthoskin. Really I'll be fore nerfing cyberlimb armor and buffing those pieces of ware. Even without cyberlimb's huge advantages looming over them, dermal plating, orthoskin, and some types of bone lacing are still overpriced. It also keeps the "few advantages mundanes have over mages" aspects that cyberlimb armor provides.
The Cyberarm of Awesome is a fairly new addition to the optimizing SR arsenal.
As I discuss here, it's a cheap and easy way for a non-combat character to become good at combat. They aren't a combat monster though. Getting two arms is pretty heavy on the essence or money (wired reflexes 2 + 2 cyberlimbs is 5 essence right there which does heavily cut into other options or requires a lot of money spent on Synaptic Boosters).
Also all-around agility is still quite good. Infiltration and other agility likely uses the legs, the whole body, or careful coordination so it can't make sneaky or anything like that. So it's a reasonable option for some characters, but nothing you gotta have.
SnS has several problems. The first is that it's weird that everyone shoots less lethal taser darts in the grimdark future. Secondly even if everyone and their dog has Nonconductivity 6, SnS are still a very good option. If the target's armor is 12 or higher, SnS generally breaks even or does even better against other ammos. For the lighter firearms like pistols, it's a net increase of DV. Going from 4P to 6S pretty much negates the bonus armor from Nonconductivity 6. Also SnS goes against impact which typically is 2 lower effective armor unless you are careful with armor choices.
If you weren't going to one-shot your target anyways (and thus honestly it doesn't matter what you were shooting at them), the electric damage aspect of SnS is really good. The -2 penalty is effectively -2 AP for the follow up shot. It also has the side effect of making it easier to hit thus in some edge cases, you might be able to get away with a narrow burst you otherwise wouldn't have. The "taze someone for 3+ combat turns" aspect typically doesn't work especially with heavy use of nonconductivity, but it's always nice when it does.
That said, the best reason to keep SnS around is to keep spirits honest. A called shot with a hold out with SnS is a threat to a force 10 spirit. Whereas a called shot with an AR with Ex-Ex is only a threat to force 7 spirit. It allows mundanes to have an easy to carry and use option for dealing with stuff mages can make with their minds. Similarily it does a good job dealing with high armor types you see from time to time.
