We’ve stayed in Sky, Celebrity and Royal Suites on the Summit on Deck 6 (Penthouse Deck). Regarding the Celebrity Suites, we love the fact that one person can get up and move about while the other can sleep or nap in the private bedroom in the Celebrity Suite. Space-wise, it’s a world of difference from a Sky Suite. I also like that the bathroom has 2 sinks and enjoy the dressing/makeup table in the walk in closet. I have found the tub/shower to be manageable if you are careful. These suites are very convenient to the mid ship elevators but not so close that elevator traffic is bothersome. The balcony, while not real deep, is in the curve that juts out in the middle of the ship so you have good visibility to see the scenery. If the upgrade price is reasonable, I would definitely go for it. Royal Suites are even more fantastic but the upgrade cost is usually much higher.