Just a bit of a discussion for those that own either of these cameras.
As the price of a second hand 5d is getting close to that of a 50d new, it's made my decision to upgrade my body so much harder.

Obviously I know the difference in specs, FF vs cropped sensor being the biggest.

My current lenses don't really restrict me in any way as I plan to get a new walk-about lens, and my current zoom (70-300) will do fine on either.

Now your probably going to say it depends what I use it for and at the moment im keen to get into portrait stuff, with a basic studio setup. I also enjoy a bit of motorsport and car photography.

So I am leaning towards the 5d purely for the high ISO advantage and I think there is just something about FF photos that you can't beat.