For the record (tested it with my own little fingers and console commands) afterburn was nerfed. It's the same DPS but it cuts off after 6 seconds instead of 10.
Yes, I noted that there was no change to DPS in a later post.
I don't think I'll really mind the 20% less damage with the flamethrower unless it affects my ability to circle strafe sentries. 20% isn't really a big deal; what's that mean, I spend another second burning a player?
The afterburn nerf however.... ugh, that was completely uneeded. Skilled players pretty much ignored it anyway as the only time it'd kill someone is if they were alone, far from health, and wasn't a class with a way to extinguish it. Usually afterburn just fed the enemy medic's ubers. So many ways to extinguish it:
1) Health packs
2) Water
3) Medics
4) Bonk
5) Airblast
6) Charging Targe
7) Jarate
Ironically, now that it only does 36 dmg, there's not really any reason to waste the airblast ammo or jarate timer on putting someone out unless they're almost dead.
Backburner needs a lot to be worthwhile. The problem with the backburner is that the airblast is already SO incredibly useful... and now with this update, it's even MORE useful. Give it old flamethrower damage and full length afterburn, and maybe it'd be alright.
The flare gun is also nerfed pretty significantly due to the afterburn. Means you absolutely can not miss that second shot if you want the mini crit, and long distance shots are fairly pointless to try to follow up. If it still had full length afterburn, I wouldn't care about the flamethrower's 6 second afterburn.
Meanwhile a demo with no heads can now slaughter a fresh 125hp class in a single charge (50 bash + 88 eyelander) without having to soften the target up with a pipe. I usually suck at taking heads, so the demo in me is going WOOOHOO!! But still Valve's main playtest group must consist of one seriously pro pyro and a completely newbie demo.
TL;DR: Afterburn nerf is freaking ridiculous. 20% flamethrower dmg reduction is no big deal. Airblast and other class uptweaks are freaking gold, though.
[Edit] Also, I reread this and it comes across as a lot more whiney/rant than I actually feel about the whole thing. Overall, once the new bugs are fixed, this could be a pretty amazing update.
Kep