Pretty odd that the reviewer encountered so many crash bugs. I played through the entire OC and never crashed a single time. There were certainly AI bugs, UI bugs, and plenty of C and D gameplay bugs in our final release candidate, but a lot of those have also been fixed in Patch 1.
In terms of overall bugginess, I'd put this above the original IWD and KotOR2, about a light year above the original BG. It's probably buggier than IWD2 and BG2.