I'm about the fifth person or so to say the shirts the CMs wear at the entrance to Epcot. I love the button-up shirts and having SSE all over it is great. Now, if only I could find one on ebay or somewhere...I've been searching for that shirt for about 3 years now.
ToT and HM costumes are great too, but I think what makes them better is the CM in those costumes, they really make them stand out more. Think about it, would a bellhop or a butler all happy-go-lucky make you love the costume as much as if it were the true no-emotion kind of CM? The role is one thing that makes the costume work so well.
I bet the Princess costumes are one of the coolest for the FL weather though. Think about, would Jasmine, Ariel, Belle or any others really get that hot as they get lots of fresh air and the breeze directly on them.