First rule of not getting downfragged: you do not talk about down frags.

Why 3 Scouts though? I'd rather play against a Sniper (with headshot only plugin).

It's already here...

You're like 8 years late with 7v7 experiments.

Wrap Assasin is godlike if you don't get to build ubers.

Also I don't think enough people here realise that Mike played like 3 seasons before he got into Prem.

Even if both teams build uber with arrows really quickly and then none of them will push, it will still save some time because they'd probably stalemate while building anyway.
Building with arrows and medi gun is made to create yourself an Uber advantage to quickly push into the enemy team. Pretty sure that's what FT did against Crowns at i58 and were quite successful.

Stalemates is the main problem of this game (except stopwatch and koth). The latest change to Crossbow brought something new to speed this up, that is why I am so against reverting it.

The idea is to build with both arrows and normal healing, so lowering the ammount of uber you get per arrow won't make a big difference unless you lower it so much it would be faster to build with just the Medi Gun. And at this point it wouldn't be speeding the game up in any way.

My Enginner experience tells me that you can't rebuild a sentry immediately. It still takes time. And if the enemy Demo would be around, he can just put a couple of stickies under it and destroy it easily.

The main idea of backcapping is going behind enemy lines unnoticed. The main idea of Bonk is to yolo straight into the enemy team. And if you do it, I doubt you'd get to last despite 8 seconds of damage invulnerabilty.

Oh please don't bring the Machina back into discussion. It has a bunch of crucial downsides.

First of all, I'm gonna be talking from 6s point of view because it's obviously the main comp tf2 game mode.

Uber gain actually speeds the game up, don't see how that's a downside. Maybe you love stalemates?
Passive reload is one of the factors, that make this weapon actually fun to use and increases the skill ceiling. Try playing Pyro with Flare Gun having no passive reload.

From what I know it's not even widely used in HL, where Heavy is run full time. Also not everyone uses it in 6s. Maybe not so OP?

It's not like a Scout can't backcap without Bonk. He'd have someone going back for him (or waiting for him on last) no matter what.

When enemy team pushes into your last and you pick your sentry up, you leave your team fighting with a 1 player disadvantage until you rotate and rebuild your sentry. This could actually lose you the point.

Did you notice 2/4 Med melee unlocks are banned?.. And Amputator isn't actually bad.

AMS went from div 3 straight to prem.

You really want to nerf crossbow, but you still haven't suggested anything.
Tomislav makes a slow as fuck class a little less slow and a bit more useful at longer range. How is that OP?
What about Bonk? It could be annoying but not OP.
RR was nerfed and is not as good anymore (plus it's countered by Cow Mangler, which a lot of people are using right now).
Razorback is a joke unless you play (lol) HL.