If you're a smoker, don't buy an Imac or a pro. Apple (applecare) will refuse to service your system even if you're still under warranty.
Just happened to me, a cigar smoker, and I'll never buy a sealed mac again.
Sure, I could quit smoking altogether, I know. But I think I'd rather make those decisions, not Apple.
If your heart's set on a mac, and you smoke; if you can do routine pc type maintenance (open case, can of compressed air, swap cards, etc) then I think I'd recommend the pro.
Wwwwhaaaat? I'm guessing they must've determined the damage was caused by the smoke, not that they refused to work on it because it stinks?
Smoking has been long known to cause damage to sensitive gear (one of the reasons I never buy used electronics).