I would tank myself for kinetic and explosive, as that covers most of the AV weapons used. Explosive armor hardener and a kinetic armor hardener FTW

Your comment made me realize that ammunition types in Dust would be nice. Every suit would have one to three slots for ammunitiontypes which you can switch through during battle. This would of course mean that we'll have to pay for ammunition though. Not sure how well that would work, especially considering mechanics like Nano hives and Supply Depots.

During the CPM-AMA, this topic was covered. One of the biggest reasons preventing development of such modules is that there is currently no good way to let others know that you have activated your hardener. The glowing effects on vehicles isn't what the devs want either, and rendering issues at range would cause problems. We would all hate it if one second we are slaughtering someone and the next second we're dealing no damage and start wondering why we are dealing no damage.

If we find that the other team is spamming Flux grenades we should be able to switch to a suit tanked to resist EM damage.

It's called Armour.

I'm not sure an audio indicator would be appropriate for a hardener as it doesn't actually turn the bullet/round away causing a ricochet but rather reduces the amount of damage that affects the hp of the user's armor or shields. There are no hardeners that can make you impervious to damage but they do reduce damage taken. Resistance implies that you have a reduction of damage so rather than take 100% of the 254 damage a mass driver is causing on a direct hit you (with a 64% resistance to explosive damage) would take 91.44 damage from the direct hit.

I see no reason for a visual indicator for a hardener other than the normal TacNet display showing how effective you weapon is against a particular merc. We have the system in place already there is no reason to change it beyond people not understanding how the TacNet system works. This could be solved by a brief tutorial upon beginning life as a Dust Merc before ever deploying to the field in the battle academy.

I agree the glow effect isn't useful for frame rate and any number of other visual reasons. Color coding hardeners on the health bar would be a positive change but how do we separate friend from foe then?

The name and chevron wouldn't change, only the shield/armor hp bar

I don't think many know how to take advantage of the damage profiles in the game.

I don't remotely see assault rifles as a problem generally.

Generally, I am fighting Caldari assaults with ARs. So I play the natural counter to them which is a Gallente suit with a scrambler rifle. Not only are they doing less than optimal damage to me, but with proficiency and damage mods on my scrambler, I am doing nearly DOUBLE damage to them. I can take a STD scrambler and drop a proto Caldari with a Duvolle in an instant because of this. Literally 3-5 hits.
I've gotten mail asking me "how did you vaporize 600 ehp instantly like that?"
The answer is simple. The fit is a Caldari Killer.

I like your thread, but what's to stop everyone from simply tanking out an Amarr suit, and say.... making shields resistant to hybrid and laser weapons, and making their armor resistant to projectile and explosives? If people hate the concept of dual tanking, that would only perpetuate the problem. As theoretically, that system can nearly eliminate almost all weaknesses.

I do like the efficiency indicator concept from EVE as well though. At the same time we have similar systems already in game right now. Right now, you ARE able to tell what suit someone has on when you aim at them, and you CAN see how effective the weapon you're using is.
What I would like is for damage mod percentage to be visibly added to the damage profile indicator when you aim at someone. So you can see, EXACTLY what your final damage tally is going to be when you shoot.

It's good to bear in mind, that we will be getting additional weapons in 1.5. These will come with their own profiles as well.

What I think would be good is a general hardener function for both shields and armor. Shields harden but don't recharge. Armor hardens, but slows you down.