I used Kylix 2 on a RedHat 7.1 machine. The only problem I had was that I couldn't run the applications (compiled) outside the Kylix environment, however that seems to be solvable by changing some config file.
For the rest Kylix itself works like a charm on a RedHat machine!

Odd problem I noted with KDE (didn't try gnome) was than when you resized the window to fill the screen and set the borderstyle to bsNone then the events where not registered anymore...

SuSe I hate, it takes control away from you from the moment you run the install (sounds familiar) while RedHat asks me a few things so I can customize the installation!