Kinda.
I went PC --> iMac --> PC + Mac Mini.
The iMac was good for day to day computing, and light gaming (i7 + 6770) but as I started gaming more on the Bootcamp installation it quickly started to show it's weakness for me. Now I know it's not a gaming machine, and I was asking a lot from it in the first place but because my needs changed it fast became a pain.
edit - Oh and after a moderate gaming session on the iMac the room was hotter than a gaming session on a PC, those things get SERIOUSLY hot!
For what I sold the iMac for I managed to build a 3570k Z77 based machine with a 570GTX, and buy a Mac Mini (2012, 8GB etc). Admittedly a lot of parts were second hand, but much happier with the setup now.
Mac for work, web browsing and general use. PC for gaming and anything CPU intensive.