I have only used Cloudrum in Logic Pro but it seems perfectly stable and sounds rather good. I actually have a tuned tongue drum but for background parts Cloudrum is very convenient and I've already used it on some of the new Cydonia Collective tracks we're working on. Add a bit of reverb and you're in hippy heaven! It responds to velocity in a realistic way and has various random/round robin options to keep repeated notes sounding natural. A lot to like.
This thing sounds awesome, but be careful using it in a track with the GUI open. Maybe it's just my setup that's shitty, but it's crashed REAPER 3-4 times on me now, with the GUI open, but goes fine when it's minimized.