When I'm playing AV I wear flak armour. When I'm in a Valk squad I use the ammo pouch or whatever it's called.
I run Adv Shields Cap + Resist it let me go back to fight faster that any other shield with Nanoweave... The only time I put it on is when I run Medic with Carapace and self heal...
Because as infantry the main thing you'll encounter is infantry, so nanoweave is mandatory for two things : -give you advantage other guys that don't have it -allow you a fair fight against people who have it IMO, nanoweave armor should be removed because having you actually have no choice for the suit-slot since nanoweave is mandatory. Also, it make headshot far more effective than they should. If you have a 125dmg model weapon on shot a nanoweave target, you need 4 bullet to kill a guy in the head, while you need 10 for bodyshot. That's actually a 2,5 headshot ratio : skill should be rewarded but not that much.
Nanoweave for all classes / all roles in my case. Partly because I am a bit lazy and it is one less thing to think about but mainly because the 20% damage reduction on everything from pistols to heavy machine guns at max rank is so useful. I frequently survive with health bar in the red after a shooting duel which means without nanoweave I'd be a goner. I'm not sure about that. I think you still get the nanoweave damage reduction on head shots although they do still count double.
I use nanoweave but don't know which shield to cert into. The default one I've got maxed out but it doesn't seem to really help me much.
Adrenaline Shield if you do a lot of killing. Resist shield if you are a more passive player who lets his shield recharge manually.
Resist is nerfed. Adrenaline is a direct upgrade to default. But remembering to hit F after every kill is a bit annoying.
Did you ever get to try one of the original Nanomesh Specialist versions on test server? It was great. I forget the tooltip but at lvl 5 it basically made it so Adrenaline shield wouldnt drain 0, if left on, and it would always hover at 1.
I run Resist Shield on live mostly and Nanoweave doesn't stack with that, so Flak armor is the best since it makes me 85% immune to explosions. On live HESH and C4 cancer are your number one worry anyway.
Nanoweave and adrenaline shield are all that matters at this present time. All the other ones are situational but don’t bank on them.
I run whatever armour booster seems appropriate. For instance as a Engineer back in the early days when we would see a lot more armour engagements on the open field, flak armour was invaluable! These days I mostly settle for using nanoweave on all my infantry except my MAX. That still gets split down the line of Nanoweave vs Flak. Flak mostly for AA ops and AT ops. Nanoweave for those pesky fleshlings.