I have bfd/xfl by itself with some vstis and other samples on a separate off-the-shelf type p4 v-stack pc (that is, separate from my Nuendo daw.) I had glitches at 512mb, upped the ram to 1gb and have not had problems since. That's going on about three months now. Fxpansion recommends 1.5 to 2 gb but I won't worry about putting more ram in unless future glitches show up.
I don't use the bfd real time stream mode, I don't use the grooves, and I also load the kits in 16 bit instead of 24...which I'm not sure what if anything that saves me in cpu load. All I know is that I (and anyone else I ask to listen) can't hear any difference in bfd when it's loaded in 16 bit compared to 24. I mean, zero difference in sound. Still sounds like a drummer who's playing right ther next to me. I just figure that if 16 bit reduces the cpu load (which the manual says it does) and I can't hear a difference, heck, I'll use it. My useage meter always stays around 20-30%.
No, this was more like, he would load BFD and everything came to a screaching halt running Nuendo. His sstem at the time was 1 gig ram, Athlon XP 3200 I believe.
Normally he could get quite a few vst'is (EWQL Orchestral, Trilogy, Atmosphere) no problems, but jst running BFD alone, the system would slow down considerably. This was also one of the 1st releases, so that's why I ask.
I've heard it and it does sound like a real drummer, however, I would hate to get it only to feel like it's not up to par as far as CPU/RAM streaming is concerned compared to other plug-ins.