I haven't even played Troopers, but from what I've read and seen I think I can say there is no comparison.
They are two totally different types of game.
Troopers and the upcoming Republic Commando are based on the "squad" idea. You have a small group of commandos that go on missions. Yet multiplayer is generally just team deathmatch, with some other fun things thrown in for variety.
While both games may have "grunt troops" as the focus and vehicles, Battlefront is more about the big picture.
We're talking huge armies (compared to your average FPS) and lots of atmosphere. There's lots of squads and lots of AI alongside humans in the bigger epic battles.
Also Troopers is focused on Rebel Commandos vs. Stormtroopers with some ship flying missions.
SWBF is all ground battles (with air support in a few of them), and covers several factions.
It's like comparing BF1942 to UT2k4 or Quake3:Team Arena. Think of it that way.
As far as Star Wars games go, SWBF is completely unique. As far as games go, BF1942 is probably the closest thing (it even has a star wars mod called Galactic Conquest).