I have to say its pretty stable. Its my main work horse now instead of P6. Just the fact I can render bigger scenes much faster with higher graphic setting makes it worth the change. I don't use the built in content so maybe some of that has problems. All older scenes load without a hitch, all old characters from v2/m2 on up load fine. I don't use cloth and hair rooms so again those could be buggy and I wouldn't know it.

I do want to add that the duplicate object function is a God send for anyone who makes sets using those set construction kits. Instead of having to load each element over and over you can simply duplicate an element and move it to the next position. Great for setting up sets, halls, tunnels etc. And it appears to save and load just fine. Only issue with it is if you try and duplicate figure that is a child of another figure, it duplicates the entire tree from the parent on down which I think is a bug.