I leveled my mage Frost and prefer to play that way but had to spec him Arcane to get invited to any sort of raid (and also for VoA where that one boss nobody ever did and his adds all seem to be immune to Frost =) ). I knew DPS was sub-par but I didn't care because it was more fun to me to play that way and it wasn't detrimental to the raid or group. True I was never top of the meters but not bottom either so I accepted it when I was allowed to stay in group as Frost, and switched to Arcane when I had to. http://bit.ly/eD3Hk9

I like Frost even more and often am near or at the top. My gear isn't top of the line or anything, but mostly 264 (with some 245) crafted/badge gear and 232 weapons. I can peak over 10k some fights with a nice string of procs. And even if I "waste" Deep Freeze on a stunnable target, I can pound him with 3-4 Ice Lances critting over 10k (often over 12k) each. I still think it's the lowest DPS of the three specs, but it is significantly better and much closer to the other two than it used to be.
http://bit.ly/g4N8lB

I have to say, though, I really appreciate how GC not only takes the time to respond to peoples' thoughts, but he also explains Blizzard's perspective and line of thought on the issues, and does it in more than just a few sentences. ^_^
http://bit.ly/gLfwNW