I should soon have ANTMiner S3.
very profitable.
Not sure I would claim it to very profitable, will barely ROI. Bitcoin investment is possibly a better use of your fiat money.
But hey, I still have 8 x s3's on order , so i'll shut up :s
Just make sure that your digs can handle ~3kwh extra.
I know that my comfortable limit (at least in summer) is ~2.3-2.4kwh extra heat and this is pushing it, which equals one S2 and 3 S3
However, I greedily ordered 6 S3 and now contemplate what to do as I don't want to sell the S2.
Selling the rest on ebay looks like a waste of time because of a small premium.