I got a commercial one for Christmas and it is aces.
I didn't want to spend the coin for a big one but found it for 2 bills
I have smoked in my basement on weekends for the last 3 weeks with no complaints from my wife except when its on she doesn't like the smell.
10 min after it shuts off she's ok.
The room I smoke in is about 460 sq ft.
Out of stock now but this is the one I have
http://www.amazon.com/gp/product/B00...ef=oss_product
Edit: I should add that after I smoke it clears the smell out very quickly, which is what I need for smoking at home.
If I had the ability to run it overnight after I left I may have gone smaller.
The price made this one hard to pass up.