mdulik, that's my intention for them too. I have a REALLY nice, fast-growing, large RIR roo that I want to cross on the biggest hens, and use some of my FIL's large wyandottes, and my one large EE hen, for the biggest of the cornishX roosters. I'm not trying to create anything too wonderful, just something that won't weeze like these cornishx do.
My cornishX have been good foragers though. But I raised them to be good foragers too. The results weight-wise haven't been as amazing as those raised to never move, but they have done fine. Just the weezing and such makes me nervous that they are all going to drop dead soon.
Ironically, it's the smaller, runtier ones that weeze the worst. The bigger ones seem healthier.