Honestly, Bitcoin mining is not profitable anymore. Any coin's mining returns good ROI in its initial stages.
Except that it is...
Buy a Cube, run it for 2 months, sell the Cube. You will end up with more BTC than you started with. I guarantee it.
Details / Links?
https://bitcointalk.org/index.php?topic=349787.60
Buy it for 1BTC, run it for a little bit... you should be able to mine close to 1BTC + electricity costs in 2 months... then anything you can sell it for is profit.
Note: It does come from a rare ASIC company that actually ships its orders out.