Originally posted by Digitalis you could have gotten a FA 31mm f/1.8 limited for that, and let me tell you the FA31 blasts the crap out of the Canon 24-105 zoom in terms of image quality.
Problem is the FA31 doesn't handle 24mm or 105mm particularly well.
As far as "blasts the crap" -- I have a 24-105 I use on FF and the only complaint I have is distortion on the wide end (the 24-70 is better in this aspect). But image quality wise it's a frickin' amazing piece of glass. When I viewed the first batch of shots from it wide open my jaw hit the floor, because I've never seen a zoom perform like this. Is it as good as the 31 image quality wise? I would think not, but it holds its own and outperforms quite a few decent primes that I've owned and used.
As for non-L lenses, there are some gems like the 85/1.8 out there. In fact, most of the "mid level" primes are pretty darn decent.
That said, Pentax definitely offers better bang for the buck image quality wise... you can get a K20D and a DA 35 for what, < $1k these days?
But if you're willing to throw some bucks at it, you can get some fantastic gear from Canon (or Nikon). My setup cost a small fortune compared to a basic decent Pentax one, but I do get something for it.