We just returned from a week in R616, one of the S4 Riviera deck suites on the Discovery, and previously had a similar one on the Sky. We haven't tried any of the other locations so can't really compare, but my impressions were:
The location was great, near to the concierge lounge and the aft elevators. It was easy to stagger over to the lounge for my first dose of caffeine each morning, and to pop up two flights of stairs to visit the Wake View bar.
The suite layout was good, with enough storage space for all of our stuff and a heavy curtain between the bedroom and living areas so the early riser (me) wouldn't need to disturb the late sleeper too much in the morning! The separate bathroom entrances were also a plus.
The balcony is indeed quite narrow. We didn't entertain or spend a lot of time out there, so it was adequate for our needs. But it could be suboptimal if you want to host a party or spread out and sunbathe.
One other note: Our suite was quite near a crew area door and the laundry room, but we never heard a thing from either.