Dave,
I've been using ac/cloud two years ago. We've also noticed some slowing with v8--closing charts and writing prescriptions. But overall it's worked well for us. One of our office computers with Windows 8 freezes up a lot but the others (Win7 and a Mac) have no big issues. I think I'm going to ditch Windows 8.
When you say that your partner has lost social history spontaneously, what do you mean? Does he complete the chart, sign it off, then reopen it to find the entered info gone?
John