I was with my SIL, aunt & mom on our June '04 cruise and we went to Topsiders. It was a little inconvenient to have to get our food first, then find a table since each of us had our "carry-on" bag on our shoulders. Juggling the tray was just a little too much, although, had we been thinking we might have sent one of our party out into the restaurant to find a table and wait for us.
Also, if you choose not to eat outside, tables seemed VERY close together inside of Topsiders. Normally they may not have been, but with everyone's carry-on bags lying on the floor or next to their chairs, it was very tight moving from table to table.
Once we saw Parrot Cay the next day at breakfast I wished we'd eaten there simply for the spacious feel of the restaurant. But like others have said, Topsiders is great for eating outdoors. Food was good too, no complaints on the buffet.