Hahaha... I love how people just give up on their storeboughts so quickly...
Seriously, I'm not kidding. Mine took 2 YEARS to break in completely. It was an amazing cube that got me to sub 20, etc. That's of course, until some maniac snatched it out of my hand and chucked it at a wall... Phil Thomas (One of really speedy dudes) uses a storebought, and his was even looser and smoother than mine.
Force the cube to cut corners, spin each side like CRAZY. This will eventually get a storebought to an amazing state. Seriously, some storeboughts are even better than DIYS.