I've got Cornish Roasters right now. This is my first time raising them and they're only 2 weeks old so I can't say how they'll end up. However, they're growing like crazy! I called MM and asked on this forum and the consensus was to restrict feed just like with the Cornish x, so I'm not sure that you'd avoid leg problems using this breed (without precautions).
They aren't very smelly which is a good thing as we have 26 in the house. I don't know how they'd compare to the Cornish x.
I agree with Cassie, it may be a good bet to get the barbecue special, then you can see which breed you like best.
If you're not ordering them right away, I can give you an update on how long it took them to get to butchering weight, health issues etc. when mine finish up...