I haven't EVER used a medkit

Even though I have them certed out. In 1200+ hours of playtime and 24,500 kills I still have not run into an extended situation where having a medkit creates more opportunity value than carrying C4 for those pesky MAXes, vehicles, groups of enemies, and any other nonsense the enemy will try to throw at you. I considered using them on infiltrator for a while, but AI mines are also indispensable unless you're sitting 250m out being useless, a popular pastime for infiltrators it seems.

Presumably SOMEBODY must use these things, and if so, why? When do you find equipping a medkit is worth the opportunity cost of giving up C4?

P.S. Okay, I lied, I used one once to see what they did.

When you have a decimator and tend to live through multiple firefights.

Infiltrators.

I've traded in the C4 for medkits earlier this year. Vehicles can be spammed, Maxes can be revived, Turrets can be repaired, my health won't regenerate without a biolab or a medic who conveniently drop podded on a roof with me.

I've never used them either. I have used the revival injections though.

I have even more playtime than OP and I have never used or cert any of the universal utilities on any of my characters. There are plenty of medics and terminals around and C-4 rocks.

Most of the lone-wolf type players I have watched videos of on YouTube and the like seem to use them. If I die or get hurt and there isn't a medic around... I find one. I think I tried the medkit when I first started playing, but found C4 and betties/mines much more important. In a game with infinite respawns, I could care less aobut the medkit.

Playing with a squad? C4.
Playing solo? Medkits.
Pretty simple.

I use it from time to time. We have enough load-out slots to have it set to use in the right situations.

I use them all the time and they are very useful for staying alive longer. They are really cheap to cert up on so why not?
C4 is pointless 90% of the time, being able to heal yourself instantly keeps you alive and means you win more firefights.

Equipping advanced shield capacitors and medi kits is also a good way of staying alive longer aswell.

I use them on my HA all the time

Med kits are pretty good for infiltrators since you get all your health back pretty much instantly which is invaluable when you need to cloak since you can't regenerate health or shields while cloaked. I use restoration kits on other classes since you get the combat medic regeneration effect which has helped me live through tons of fire fights and escape many near death situations.

I use C4 on my medic and LA only because the medic has self heal and I have no interest in stacking health regen and the LA due to it being able to circumvent most obstacles and place C4 easily.

Proximity mines are nice but so is not dying. A lot of times proxy mines are blown up by hostiles or they might not kill them even if they explode by proximity but my SMG will.

I have load outs with Restoration/Med kits for all my classes as well as mines/C4 load outs, I use the Restoration load outs more when it's time to brawl lots of infantry and just shoot maxs in the face at a bit of range while hiding from those pesky vehicles.

I didn't know how they worked until like 4 months ago. I tested using it a little then went back to other stuff.

I use medkits frequently on my HA when I'm not running with the outfit, still haven't bought C4 for my heavy as I already have it on my LA. Also have started swapping all my infils loadouts to med kits but that's more because claymores are now completely worthless instead of just mostly worthless for TR.

I use them on my HA often

On other chars I run utility

Theyre great if you are a soloer. If you run in a squad with proper medics, they arent really necessary.

I like to be a frontline HA player I can't be without them. I tend to be the first to cross the open field, first to the base wall etc. Usually take my hits running between cover to get in close and personal, any medics are far behind and typically I am out numbered. 4 med ktis provide an invaluable heath bonus for extended survivability

I use medkits constantly. When I go up against skilled opponents, it often comes down to who can pop a kit where survival is concerned. I can't tell you how many LA's or Inf's poop their shorts when I get shot, pop a kit raise my shield and shoot them in the face...

Most of those guys are "noobs" or casuals though.

When going AA as infantry (HA w/ missle launcher) my build is usually anti-HE armor and a few med-kits. I rarely get killed when in this mode.

Med-kits are a serious life extender that people almost NEVER use.

Other than getting some decent xp, I think most medics are played simply to have a ready self-heal ability rather than to support friendlies, unfortunately.

Eventually, some of those folks migrate to other classes once they understand the utility of the med-kits.

If I had the EM6 or NC6 I wouldn't ever use a medkit either.

Don't agree, I would rather have my squads combat medic actually participating in the combat, every gun counts.
IMO medics are there to get you up if you go down, not squire behind you healing regular damage that can medpacked in 0.5 sec.