Yes, these are average, typical complaints, aside from the fast-forward issue (haven't seen that one myself).
Personally though I get along fine with the HDUI. It's often an Internet connectivity issue that exasperates this problem. The box still doesn't handle less-than-perfect Internet connections gracefully. As such, you might want to look for connectivity issues (wireless in particular, if you're using that).
As far as Netflix and Amazon plugins, you're seeing the cobwebs and layers of dust that indicates the programmers haven't touched those apps in a long, long time.
Personally though I get along fine with the HDUI. It's often an Internet connectivity issue that exasperates this problem. The box still doesn't handle less-than-perfect Internet connections gracefully. As such, you might want to look for connectivity issues (wireless in particular, if you're using that).
As far as Netflix and Amazon plugins, you're seeing the cobwebs and layers of dust that indicates the programmers haven't touched those apps in a long, long time.