The need for a debate of this type always slays me. They are two different animals because of the rules. One example is the wider field and having the d-line a yard off the ball requires a bit smaller and more agile offensive linemen.
I'm a HUGE CFL fan...have been for about 5 years now and the caliber of players in the NFL is definitely better than that of the CFL. But so is the level of athlete in DI football to DIAA, DII, DIII, etc. and on down to juco and high school. That's not to say you can't watch some great, exciting and entertaining football at the "non-elite" levels. It's more about the level of competition being relative to each other, having well coached athletes, good game plans, etc. Many, if not most, of the CFL players are just a slight notch below their NFL counterparts...good, but just not good enough.
It's a spectacularly exciting brand of football to watch.