I liked both, although I found 2-3 bugs so far on the PC version. Nothing a little patch can't fix.
I've progressed much farther on Xbox 360 though.
Have you done 4 person co-op LAN?
So you are ripping on it for the graphical style? I have a suggestion for you, if you can (will be hard) find a copy or a torrent of the game XIII. It's a first person shooter game that has a similar cartoonish style of art. The whole game consists of you going through a comic book, as you pick up info and do main things in the plot, more of the comic book will come together. It's a great and very underrated game that flew under the radar.
Also, I prefer the cartoonish graphics, if only because of the question, "Why would I sit in front of my computer to see real things when I can go outside?". It's a video game, and it's all about fun. I enjoy a game if it's fun, not because of the visuals. And because of that, I take an elitist standpoint as a gamer because I can judge games on playability, not graphics. =p
p.s. I dislike tf2 as well, just not fun.