Yes.

Started just shy of 2 months ago.  Dropped *LOL* many thousands of dollars on hardware.  Would EASILY have more if I was able to drop more power into my place.  I'm nearly at my limit and more machines will end up tripping fuses.  =(

I'm limited by electrical supply.  No problems with space, noise or heat.  I would need to go commercial or move my machines out of my residential to grow if I wanted to.  Regardless, I'm quite happy with this whole operation and even if everything collapsed today, I wouldn't care much.  I don't know what I'm going to do with this many 5xxx/6xxx cards after bitcoin tho.  I'm going to have alot of happy family and friends tho.  I plan on just giving them away to them.  They can duo/tri/quad them.  =O