I had a Genesis Altitude 20 that I built up into a pretty lightweight race bike. I really liked how it rode. I used it from xc races to 12 hr solo stuff. However in the end I felt the frame was the overly heavy (well apart from me!) part of the package. So I bought a Scott Scale 35 at a reduced sale price. The Scale 35 has a carbon frame but fairly low end components. Before I even rode the Scale I swapped all the bits between the frames and ended up with a much lighter bike. I still have the Genesis and it has gradually ended up as a slightly more burly bike than it was before.
Between the two the Genesis is easier to ride, the Scale is a bit more twitchy. Uphill the Scale is faster. If I had to make a choice and could only keep one it would be the Scale, it is great as a race bike, but also fine as a weekend general riding bike.
Sorry that probably doesn't help much!