It didn't feel any narrower than any other Cat V or other Family w/verandah we've stayed in. I didn't find there to be any obstruction. Yes, you can't look all the way down the side of the ship because of the bumpout, but that wasn't an issue for us. We had plenty of room on the verandah, but I felt that the deck 11 verandahs were actually deeper given that they all have the terrarium overhead, which extends beyond the edge of the deck 12 verandahs. This could be an illusion. I could look up from our deck 11 verandah and see the people above on deck 12 without having to lean out, though. Looking at video of deck 12 and 11, deck 11's verandahs *are* quite a bit deeper.
11000 *does* have a smidgen of a bumpout, though. You can see it in this video at 5:20: