In my opinion, the ground or away missions are not fun. I'm really enjoying the space combat but for me the ground missions are not fun. As a result I just rush through the ground missions so that I can get back into the space combat.
What I don't like about ground missions.
1) Can't move at the same time as I shoot. Must stand still while shooting.
2) Can't strafe at all. You can double tap a key to make him dive side ways but not strafe.
3) Don't like pressing number keys to shoot. I would prefer to use my mouse buttons to shoot.
Ground combat would be much more fun, at least for me, if the ground combat was more like a first person shooter or even third person shooter. Mass Effect 2 comes to mind since it has decent ground combat. I personally prefer freedom of running and gunning like first person shooters and if well done I like playing third person shooters. Maybe other people enjoy the ground combat in this game. I can only speak for myself. So for me, I don't find the ground combat very enjoyable in Star Trek Online. It's only passable.
So I guess what I'm saying is that at least for me, the ground combat is the weakest link in this game. I'm glad that ground combat is only around 30 percent of the game.
In spite of that fact, I am still enjoying the game... so far. We'll see in couple of months what the lasting appeal of this game will be. I think if they improve their ground combat missions making them more fun to play, then the game has a chance to last a long time.