Yep, big thumbs up to the devs. I used the latest version this afternoon for a couple of hrs without a single crash. Plenty of playing with geometry, variation shader, uv editing, etc and it was flawless and really fun using the IR.
I've found a bug I haven't seen elsewhere but might have missed it.
The environment tab in settings with the overrides for background, etc doesn't work when using the IR. Still seems to work fine when doing a final render as before.
Well looking forward to the next build.