All current APS-C (crop) Canon bodies have outdated sensors with mediocre noise performance and dynamic range. Those cameras are good enough though: the outdated sensor doesn't mean you can't take great photos. However, you might be able to get a better camera for less money with another brand...
I think currently the 7D only makes sense if you see the large body with large controls as a positive point, and don't want to invest in full frame (yet). Canon offers fuckall for crop lenses, so you will end up with a full frame set up with 1.6x crop sensor (this is what Canon wants, so you'll upgrade).
On the other hand you can get micro four thirds cameras with better sensors, better focusing, smaller bodies and sharper lenses than Canon APS-C. It is worth looking into, as well as some other mirrorless systems (Fuji X).