The thing I like most are the stories with voice acting by the original actors. A lot of the actors of the various series have lines, even some of the Original Series cast, like Leonard Nemoy. The stories are well done and the voice acting is the one great advantage over CoH. You can easily do those stories with basic random Mark 12 gear that is very easy to get by max level. Levelling is also easy, everything gives tons of XP, I have a level 34 character that hasn't left Star Fleet Academy yet.
You can get up to Mark 15 gear, and also sets that give extra bonuses, mostly through long grinds, but sometimes also through mission rewards. It's like going from SO enhancements to IO enhancements to IO enhancement sets. Lots of the improvements are behind long but not very tedious grinds. I do think there are too many stupid grinds.
The costume designer is ok-ish, on the Klingon side it is decidedly MEH, especially if you don't play an Orion.
There are only 3 roles: Engineer, Science, Tactical. This doesn't really matter in space, where the kind of ship makes the difference, but on the ground your character's abilities matter. I like Engineer the most so far.