Tim wasn’t kidding — Adium for OS X (based on Gaim) is awesome. I had been using iChat on my OS X box at home until I picked up a bunch of Yahoo! Instant Messenger pals in my new job. I tried Fire for a few weeks, but it left me cold. Honestly, I never really liked iChat that much either, even after exhaustively going through its preferences and stripping it down interface-wise as much as possible (getting rid of the text bubbles, the sounds, etc.)
That being said, I hadn’t spent any time looking for alternatives, but two minutes after reading Tim’s post, I was up and running with Adium. Easy switch, and totally worth it, though I recommend disabling the sound effects immediately — I jumped out of my seat when the first IM came through with a loud “QUACK!”
iChat and Fire are both gone from my dock now.