I've just discovered the most effective way to kill large numbers of infantry. Get a bunch of people on flashes, get them up max speed and jump off they'll run right through them and kill them, I know this because I got chased down a corridor and hit by one that had no driver.
It's pretty hard to aim and hit people even if you are still on and trying. Even if the enemy is cooperative and standing still.
Team mates, on the other hand, tend to be pretty hard to miss. Fortunately collision detection is dodgy and I've managed to pass straight through medics and MAXes without team killing.
I'm strongly considering buying a gun for the Flash, simply because I was driving behind a TR on his own Flash for nearly two minutes trying to work out how I could kill them. I stop, they keep going and I lose them in the ground clutter without getting a shot on them. I wait for them to stop, they get to open fire first and choose the terrain. In the end they hadn't even noticed me when they parked to enter a base and I got the jump on them when they headed to a capture point. But still... having something I can fire from a moving Flash would be fun.
I now officially have more MAX punch kills than scattergun kills. Was playing AA again and kept having to charge and melee with TR infantry. The flak looks like it does OK damage but a single HA can out-tank a double AA MAX while exchanging close range fire. I pulled that off earlier as well. Admittedly I had the flak armour accessory equipped which seems to help a lot.
Speaking of the armour certifications, here's what I've gathered so far. A mix of forum reports, personal experience and a little extrapolation, so don't take this as gospel, but it's the best I can do so far;
Nanoweave armour;
Reduces damage done to health (not shield) by 5% per level, up to 25% at level 5. Numbers approximate given the very limited testing done.
Currently has a bug associated where you may die before losing all your health or where your health doesn't show as lost at least, as well as some other health bar weirdness.
Flak armour;
No real tests on this so can't give numbers.
Reduces explosive damage by a notable amount. Seems to apply to shields and armour/health. Appears to apply to non-obvious sources that are flagged as AOE damage. I even seemed to take less falling damage. This all could just be random bugs and confusion.
I'd be up to testing this if anyone else has an NC character on EU1 and some explosive weapons they can shoot me with (and accept the eventual weaponlock on).
Advanced shield capacitor;
[Note, haven't personally tested this.]Reduces the time before shields start recharging.
Reportedly a 1 second reduction per level, up to 5 seconds at level 5. This is subtracted from the default 10 second wait.
Some reports that it's actually a 0.5 second reduction per level. Different classes? This is differently priced (much more expensive) for HA than the lighter classes.
Grenade bandoleer;
First level for the second grenade is cheap enough and well worth it in a lot of situations. Being able to frag two rooms instead of one can be invaluable, or lay down a more smoke as a LA. The second level is stupidly costly for the third grenade and balancing it against the armour upgrades makes it hard to justify. I'll probably look to unlock it on the medic if I ever play one long enough to want the res grenades.