Hi! I haven't been in that particular cabin, but we've been in #1100, two decks above. The balcony gets smaller the lower you go. It's not real wide, but it's definitely deeper than the other cabins in that category on the side of the ship. We walked by the same category cabin (next to us - #1102) and the floor plan was the same as all the other cabins, but the balcony was like a long, long narrow-ish space. It was partly covered. The cabin you're talking about would be maybe 2' less deep than the one we saw I would guess. The only drawbacks are:
1. The really long walk to the elevators (the staircase in the brochure is for crew only)
2. The morning noise when the ship pulls into port (it's REALLY loud!)
If you can handle both of those things, then go for it. The balcony is really nice!
When is your Radiance cruise in that cabin? We will be in that same cabin on Brilliance in Nov. If you are going in Aug., Sept. or Oct. you can tell me about it; if you're going after mid Nov., then I can tell you all about it!!