We tried Captain's Grille for the first time a couple weeks ago and were, on the whole, pleased with our meal. DH had the strip steak (excellent!) with mashed potatoes (horrid, very dry and lukewarm); I had the trout topped with some sort of vegetable concoction (the olive tapenade was very salty). The ceasar salad was HUGE, enough for two to share, and wonderfully tasty.
Did not see anyone eating crab legs, so I can't comment on how they looked. We had just eaten at the Beach Club's clam bake restaurant the night before and had OD'd on crab legs (if that's even possible), so I wanted something different this night.
It is a great spot for escaping some of the busy-ness of the parks, and super convenient when returning from a day at Epcot or the Studios. Our reservation wasn't until 8:30, and there were only 4 or 5 other tables being used. The waitstaff did say earlier was very busy.
Enjoy!