Playing pyro has become more like a challenge against odds. It's become situational to the extreme. However, I still think that the Engineer should be outright removed and replaced with a fun class.
Yes, this is a rant against engineers.
The most balanced point I can come up with is that they only manage to slow the game down, other classes do his job pretty well, so engies serve pretty much as a speed bump, and while they can help stop a team that's advancing on momentum alone they'll quickly fall when the enemy reorganizes. All in all, their most important activities are building teleporters and dispensers on offense, so long as the game doesn't stalemate they won't even need to set up a forward base. On defense there's very few places a sentry will be useful for long, and if they wanna go offensive they rely on luck and should expect a lot of frustration. TF2 plays far too fast to have a speed-bump class like the engineer.
Ok, I'll stop ranting here.