I think you need to bear in mind that forums like this are places owners actively seek out to go and complain or get a solution to a problem. In reality compared to the number of phones being 'dished out' the failure rate will be relatively small.
I guess you're right. I think I was just a little bit startled when I was reading that some people were up to their 4th 928 replacement, which, to me, was staggering, since I hadn't seen that over in the 8X forum.
Either way, I love my 928.