Originally Posted by rowan

If you can afford it the 5D is the new kid on the block. It's full frame (no 1.6X crop) which means that all your lens purchases are more future proof. EF-S lenses such as the 10-22mm are not a good long term investment because their use is limited to the digital rebel or 20D only.

On the flipside, the 5D is probably about twice the cost, so if you need "super" wide angle on the 20D or dreb then the 10-22mm is the only real choice...

(Wanna talk about super wide angle? Try a Sigma 12-24mm on a full frame body. )