All of the cabins were about the same except for one "owner's suite". I looked in when it was being cleaned. It had a separate living room area. I'm not sure it would have been worth the money.
The difference between an A and a B cabin was that B was on the lower floor. You have to climb an extra flight of stairs to get to the main levels. I didn't find that was an issue. Read entire member review.
Cabin 140 was the last one at the front of the ship. It was VERY noisy as you hear the bilge pump loudly running constantly and the door to the crew stairs is just outside so that is slamming constantly. Better choice is to stay in the middle of the ship. The cabin is also showing wear and tear. The toilet flushing isn't great (even paper doesn't go right down) and there is rust around the door frame.