Donny, I have had zero problems with mine and I've been using it 5-6 nights a week for many months.
I haven't updated to 4.0 yet. I've sort of been waiting on the sounds and styles, but also to see if anyone has problems related to the update.
I have owned almost every arranger ever made, and this one comes closest to satisfying my every need. It sounds like a live band playing, is easy to operate and has been totally stable.
Perfect, oh no, but I certainly don't regret buying it, and only look forward to the improvements yet to come.
A couple of the issues on which non-owners have obsessed are really non-issues to me.
DonM