So far, I'm liking it.
One big difference is you have to earn points and gold to unlock light and heavy armor. Not too much of a fan of that because it gimps your team if everyone can only roll medium armor.
Having a spinfusor back in my hands was pretty nostalgic and I almost creamed my pants when I had my first spinfusor duel.
One nice thing they added is a "ski" button (spacebar). Not sure if they had that in Tribes III, I never played that, but I know it wasn't in Tribes II.
So, when your jetpack runs out, if you time it so your coming down a hill into a valley, you can ski down the hill, building up enough speed to ski up the other side and pop the jetpack when you crest the hill.
Skiing isn't new to Tribes of course, but it definitely seems like they spent some effort to more fully intigrate it into the game play.
So far I give it a thumbs up and would definitely buy the full version, especially if we could get some LoD playing.
Thanks a lot for the key Slaker, much appreciated.