Didn't see any difference in the information provided re Keep door or wall health. I did note that the target buff bug hasn't been fixed in FTC, though. Mouse over a target and their long term buffs are displayed and then don't go away until a new target is acquired.
Also what's up with the group units? They poorly show shields and don't show HOTs.
I don't see a compelling reason to go back to FTC.
I like AUI because it is fast, gives better FPS, doesn't cause errors (because it is up to date (duh))! It looks better, has a mini-map, much more customizable, flashes when Combat starts, has individual modules that are cool and customizable and, last but not least, ALL the kool kids are switching to it now!
Best thing on FTC is the Grp Dmg Meter to see how much dps your group does, but only if they use ftc and have that option enabled. Actually i use LUI for Everything and AUI only for that extended Quickslotbar and the Minimap