I alway update to latest version of KS. I try it out and if it seems stable I start using it. Numerous times I endup having to switch back to the older version because of an issue. It is a pain to have to redo all the work again in the older version. It really would be nice to be able to save those files done in the newer version back to the older version format instead of redoing them. Most software allows that.
KS 8.1 has been pretty stable for me, what are the issues you've been encountering?