Since I’m an opinionated jerk off, I’d like to take a moment to discuss what I think about the augments in the game one by one. And…you know I guess you plebs can state your opinions too. 
The fact that a few of these even exist is questionable honestly, which is kind of the point I want to make.
Big Ears: I guess I wouldnt say its completely useless? Defiantly a bottom tier perk as most of the time people are going to just start shooting you. Phantom already makes a massive humming noise when he’s close so…whatever. What really does it though is the amount of explosions going off, which would drown out any nearby footsteps with or without this perk.
Biggerblast/explody: Yes, on any character. Top tier perk, especially for Kira and Arty who already struggle with radius on their abilities. Skyhammer and Fragger benefit less I think for various reasons, but its still far from a bad perk on either of them. Take that shit if you can.
Bombsquad: Bottom tier perk on any character. Proxy is barely used at all in comp, and even if she was…just look down before you enter a room. The other explosive using characters are going to be throwing them directly at you, so unless you want your murder in HD, ignore this perk.
Chopper/quickslash: A mid tier perk. Its nice when you’ve got it, and is noticeable when it comes into play. I tend to get into a lot of melee scraps for some reason, and I usually win. So for me, chopper is nice. Im sure plenty will disagree with that though, and I dont blame you.
Cool: A mid tier perk on chapel. Sometimes an air strike misses and leaves jusssst a little on the health. On chapel specifically, the EV is in view of a machine gun nest the entire game. All other maps though? Likely a bottom tier perk. You shouldn’t be on an MG that long if you’re facing competent players. Your cute little head is just too exposed.
Doubletime: Awesome on the faster characters! They can make good use of this to harass the shit out of the enemy. For my playstyle not so much, but I wont begrudge people who like it at all.
Drilled: Top tier. I dont think I need to comment really, its faster reloading. Especially useful for handgun encounters where both of you are dry on both weapons…guess who wins that fight?
Enigma: Im not really sure to be honest. You can destroy the HBS or shoot Redeye to end the spotting effect a lot faster. Likely a bottom tier perk, might see more mileage out of people like Proxy who run around a lot.
Extra Ammo: Most likely useless. Your packs regen fast enough to keep everyone going in a 5v5. Maybe in an 8v8 its better, but at that point theres bound to be another ammo person doing his/her thing. Bottom tier.
Extra Supplies: Useless on Ammo stations, decent for ammo packs, an absolute god send for healthpacks and the healing pulse Take this on any medic you can.
Fail safe: Why does Arty have this? Good for Fletcher and Nader. If you need it on anyone else, stop eating paint chips.
Flying Pig: … An absolute insult to my intelligence, and Im pretty god damned stupid. I didn’t even know there WAS fall damage in this game until I read this perk. I’ve never taken any, soo…
Focus: Awesome for Fragger and any of the snipers. Less so for anyone else as you won’t be ADSing that much. Mid tier perk i’d say, certainly better than flying pig.
Get up: Top tier perk for sure, but an absolute necessity for Sparks. Take if you can on the other medics, and if you aren’t using the 383 for her Im sorry to say you’re just doing it wrong. I would say Phoenix gets the least out of it, as a healing pulse can be dropped pretty quickly. I like his obsidian card loadout a lot, and it doesn’t have it.
Guardian Angel: Paid 3000 gold and never used it. Wait…wait… Oh you mean that one? Shit. I didn’t even know what the audio cue for this was for a long time. The usefulness of this perk boils down to how much you pay attention or have teammates that actually use their damn voices. Bottom tier…you can hear Skyhammer a mile away most of the time. If that doesn’t get your attention, nothing will.
Healing reach: I can put my health station a little further back? shrug ill take it. Mid tier perk for both of them I’d say.
Ice cold: Nitro is better.
Lock-on: Play with it, and play without it, and then you tell me how awesome it is. It makes the shotgun almost worth taking on Fletcher.
Looter: I actually don’t hate this perk. Mid tier, its saved my ass a few times.
Mechanic: Mid tier. Sometimes engineers die and you have to take over. Wish it would override people without it.
Nitros: Comes with unshakable on that card, Rhino’s number one perk. Take it. This a decent perk too, as spin up time isnt something you really want to deal with.
Pinapple juggler: top tier perk for lols. Best noob trap ive ever seen in any game. There is nothing, NOTHING more hilarious then watching level 3 proxies chase after grenades.
Potent Packs: God tier. Take it on any medic you can.
Quickcharge: On the 383 Sparks card, you’re pretty much defaulted to this. Which is a good thing, as its an amazing perk.
Quickdraw: good for the Stark and BR-16 as well as Fletcher who has to switch up constantly. Anyone else…meh.
Quickeye: Awesome on the Stark. Anyone else…meh. I don think the snipers get it do they? If they did, it would be a good one for them.
Spares: Not a bad perk if you don’t have a fire support worth a damn. Mid tier i’d say. Never hurts to have more bullets.
Springy: You know, I hear a lot of people swear by it. I dont get it. I’d much rather have something else 99% of the time.
Steady: If lock-on is option, its better. I think the only perk to have them both comes with the Blishlok? KEK is better for most people, and lock-on is better all around. Not a bad thought though.
Sneaky: Read big ears. Worthless.
Spotter: I wouldn’t say its useless, but dont go outa your way for it. Mid tier perk.
Tough: I guess there are worse perks. Its not bottom tier, but its pretty close.
Tryhard: Kinda like toughness. Its an extra 10 health every so often, 20 on a bad streak. If you get to thirty, youre doing something wrong. Not useless, but no great.
Unshakable: Top. Tier. Perk. You know all of those explosives? Yeah, they don’t hurt as much. Surviving with 2 HP and disarming the bomb is a beautiful thing. Suck it Fletcher.
Untrackable: Its ok I guess, good for sneaking around turrets and dodging mines if your too antsy to look into a room before you walk in or are being chased. Might save your skin a few times. Mid tier.
Well thats a wall of text, but hopefully itll be worth it.