I play both X-Wing and Star Trek Attack Wing and honestly greatly prefer Star Trek because of the many diverse missions, over a dozen factions so far, wide variety of space terrain, epic scale, and amazing amount of crew, captains, weapons, and tech that you can outfit your ships with.
X-Wing is almost always a fighter skirmish between the same two factions amid exactly six asteroids with no storyline and after a while just feels like a chess game of moving game pieces.
In Star Trek, you might be fighting over a planet while in space and on the ground, having to choose to lower your shields and beam reinforcements to the planet or concentrate on the space battle above the planet first as seen here in the Siege of AR-553:
https://www.youtube.com/watch?v=U28JKCBNtr8
Or you might be fighting over a space station to take it over and have to choose which crew you can spare to man and defend the station while fighting off an enemy fleet also battling to take the space station as seen here:
https://www.youtube.com/watch?v=pa0E9X3py88
Or you might be battling throughout a 5-planet solar system as you try desperately to stop the Borg from assimilating planets so your fleet meets them at the opening of an asteroid field as seen here:
https://www.youtube.com/watch?v=v_HwEos7exc
There are about 50 (yes - FIFTY!!!) scenarios so far and I have reviews of over thirty of them complete with videos of each in gameplay here:
http://boardgamegeek.com/thread/1112810/compile-reviews-and-videos-staw-missions
I play both and enjoy both but X-Wing gets a bit stale after the same scenario over and over and over while Star Trek never gets stale because of the astounding variety of factions, starships, scenarios, terrain, captains, crew, and everything else.
Edited by Stormtrooper721