yep, at least it is for me.
I think its the UBT, its wild how they make that thing work.
BUT, it means a new rebuild every time you download a big change. It seems to handle normal editing just fine. but a big change and yea, I clean and rebuild. It clears up all sorts of problems.
It gives the added benefit of a clean new build in any case. I just plan on having dinner or something during the hour rebuild process.