Did you look at the amazon feedback?
Did you look at the dedicated R550A thread here at AVS?
My endless reminder to folks looking at Amazon feedback. NEVER have it sorted by "most helpful". That's a self-fulfilling thing. The first few reviews there are the only ones that are ever read, and they get the hits, etc.
And sorting by "newest" is incredibly important because hardware & firmware revisions change over time on these things. Many complaints vanish as the manufacturer learns and solves problems. They can also introduce new problems. Also, many times you'll see a lackluster 3 star review for something, but when you sort by time you'll see everything recent is 4 or 5 stars.