Pool - Nicest pool is Harrahs Marina. If you want a pool for swimming laps, go with Borgata - they have a dedicated time for swimmers. Caesars only has an outdoor pool. You can use the pool at Ballys if you stay at Caesars, but you have to pay.
Rooms - At Caesars, for a regular room, request the Centurion tower. It was renovated last year and is very nice. Avoid the Temple Tower. Some of the rooms have no windows. The Borg has nice rooms, too, but housekeeping isn't what it used to be there. Harrahs has a new wing that's supposed to be very nice, but I've never stayed there. The games suck at Harrahs and you have to travel to play.
Food - Best buffet is at the Borg.