I downloaded the beta yesterday and woke up this morning and all of my contacts were deleted. I had to roll back to ios7. That's a pretty big bug. Other than that my experience with iOS 8 beta 4 was pretty good. Has anyone else experienced this?
Do you sync your contacts with iCloud or google?
The important part is that it doesn't actually delete your contacts. I can deal with contacts being turned off in iCloud by some weird bug but losing all contacts is another story.
For what it's worth I've been running iOS 8 B4 since release and it's pretty damn stable for me.