I had the 12'' version in my house for two days. I hooked it up, calibrated my system, fired the "bad-boy" up, started laughing, messed around with more calibrations, looked at it and said "cute", boxed it back up, took it to BB and got my money back.
The sub is not the place to skimp. Save your money until you can get one that will handle your room. The Parts Express DIY subs may be a good option for you.