Todd's review was pretty much on the money. Part of the problem on this cruise was that there were 4+ sea days on the way to Hawaii and what seemed like even more on the way home. For most of those days, it was too cool to be enjoying our balcony and outdoor activities. That isn't the cruise line's fault.
I've cruised Celebrity and Disney before, and I think that the Radiance has too much wasted space in the Centrum. There just is not enough room in the public rooms for the number of passengers aboard. You go an hour early, or you stand.
There were not enough activities to keep people entertained. For a fourteen-day cruise, there was one wine tasting and one cooking demonstration, both on the first full day of the cruise. There were probably a maximum of thirty seats in the bottom floor of the Centrum where the cooking demo was held. I took one look, and decided not to stand through it.