From what I understand, and have heard, TM has been a bit unstable lately as far as Ca, Mg and PO4 go... now that said, TM has been a lot of people's favorites for quite a while and there are a lot of people that swear by it. I used TM regular premixed from RCA for my smaller tanks, but after starting up the 115 I've started mixing my own using Red Sea Coral Pro, and I am really liking it.
I know there are several people around here (TexReefer included) who are using Reef Crystals with a lot of success, and with so many people using so many different salts yet still having great luck and success, it's really difficult to pick a salt brand.
Here's why I chose RS Pro:
-cheaper than TM
-easy to get
I do have to mix my batch at least 24 hours before my WC, which is a pain for some people, but doesn't bother me...
I don't know if this helps or further confuses the subject but most of this is based on unprofessional research of my own and other people's experiences.