Seven pounds finished weight is great! I wouldn't sweat it....he may have bigger birds but I'm betting yours will taste better and had healthier lives. I'd do a taste comparison!
That yellow color his had is extra fat underlying the skin...not necessarily a good thing if you want good, lean...
I would agree with the other posts. A free ranged CX won't be lying around by a feeder all day consuming calories. At least...mine didn't. What were your friend's finished weights compared to yours? Did you provide plenty of fresh water? This plays a big part in their development and...