Of course, if all three bonuses of MBW scale with rating, you're still looking at +3 dodge and +3 REA for MBW3 over WR3, for 75k.+3 to dodge is only usable if you have dodge skill at 6 and the +6 to REA is in most cases totally excessive(normal max is 9 after all)
And as i said that 75K is almost enought to get alpha ware wired reflexes which frees up a ton of essence.
I agree on the 75k vs alphaware trade off.
And while the total +3 dodge is only fully useable if you already have Dodge 6, it guarantees that no matter the situation, you will have the highest modified Dodge you can have (ie, at Dodge 2, you have Dodge (3), Dodge 4 becomes Dodge (6), etc). And, it means that you only need to bring your REA up to 3, if you know you're going for MBW3. I can live with REA 3 (7) (MBW2) from game start to the point of getting the money/connections for MBW3. For many street sams, that probably frees up 20 - 45 BP* to stick elsewhere (granted, some of that's going to the MBW 2...).
*Sample Street Sam in SR4A has REA 5 (7) due to WR2, going with MBW2 (costing an extra 10 BP, plus Restricted Gear at 5 BP), you can lower REA to 3 (freeing 20 BP). This is a net gain of 5 BP, which can go straight into Dodge, giving an effective Dode 1 (2). And that still leaves 1 BP which could go into Gear or Contacts.