I just released a 1.0.3 update that should make Ray-V usable for just about everybody.http://sourceforge.net/projects/libmodsynth/files/
I've fixed a few bugs, but this release is mostly about hardcore CPU optimizations. This is the approximate CPU usage I'm getting on my desktops PCs now.
Patch: 2 x 7 unison saw oscillators
Benchmark: Play 8 notes simultaneously
AMD Llano quad-core APU, 2.6ghz
CPU usage: 50% of one core, no Xruns
AMD FX-8120 8-core, 3.2ghz
CPU usage: 30% of one core, no Xruns
...which should alleviate most people's Xruns. The patch wasn't playable on either machine before, so it was probably about 200% of one CPU core, so this should be a huge improvement for everybody.
The only 3 bugs I know of now are:
1. Controlling the knobs with a MIDI hardware controller doesn't work properly (although host automation does)
2. Rarely, something weird happens at startup and it only makes a clicking sound when you play a note
3. The first patch isn't loaded when you first open an instance of Ray-V(a tradeoff for fixing a more serious bug)
As soon as I can fix these bugs(and any other bugs you report), I'm going to start working on the 2nd plugin in the series, which will be more advanced, with flexible modulation and wavetable oscillators.