I have the Renaissance Bass running on a Mac Book Pro with a 2.2 Ghz processor and 4 GB of ram. The software works exactly as it should on my machine and I never had any problems using it. My machine is pretty sturdy and is able to handle a bunch of plug-ins at once, but like all plug ins, R-Bass will only take you as far as your machine will allow it to.
I've been using the Waves R-Bass for about a year and a half and since then I have put it on almost every bass guitar track that I have recorded. It adds a fullness and depth to the bass that is hard to live without after hearing the difference between the signal with and without the plug in applied to it. It is incredibly easy to control as it only has three sliders - one for intensity, one for gain, and one to set what frequency you want to boost. Since it is designed especially for bass instruments, the frequency range is pre set for frequencies that will enhance the bass in your mix. I haven't been able to find any plug ins that do the same things that Renaissance Bass does. If you get the R Bass in plug in pack, it really isn't too expensive and is definitley worth it as you won't be able to live without it after you use it! All in all I'm a big fan of R-Bass and would recommend it to anyone who wants a generally richer bass tone!