I'm going to say use trinity just for its EASY keybinding, and simple to use and create setups.... especially the macro system (you dont even need to use wow macro's you can macro right into the buttons in trinity lol !)

only thing i seem to find is trinity kinda is heavy on its mem usage not exactly sure if its just me or not... i love the fact that you can keybind stuff RIGHT inside the spell book, i run a prot pally and 3 mages for my team, and spamming fireball or scorch or frost bolt or whatever i want, can be done right out of the box with a simple keybind in the book