RHEL tends to only backport fixes for selected hardware so support for suspend resume, power management etc tends to lag behind quite a bit compared to Fedora (having rock solid stability and the very latest software isn't really feasible) but RHEL 5.2 + does have some of the latest desktop software include OO.o 3.x, Firefox 3.x etc.
There are tends of thousands of customers using it on their desktop, workstations etc so it not just a server distribution. As a rule of thumb, if you are not using the very latest hardware, it would likely work just fine.