I've owned this game for a very, very long time and with my mini-convention coming up was thinking about doing a Star Trek scenario. I wanted to try it out, however, and decided to run a one-shot using the Last Unicorn Games version of Star Trek.
I'll say first off that PC creation is a cinch and only takes a couple of minutes if you use the pre-made packages for their early childhood, training cruise, etc. There's enough options for ship positions to round out a five-person party easily without someone having to be "Ship's Counselor," which I think would be a dull position in most cases.
I will say that the dice mechanics, as it played out in the scenario I designed were odd. When you want to make a skill check you roll the number of dice equal to the applicable attribute, pick the highest die (they are all d6's) and then add the skill rating value. So if you have a skill rating of 2 and an attribute rating of 3, you roll three d6's, pick the highest (say, a 5) then add 2. One of the die is a "drama die" which when it is a 6 you can take the 6 and then add another die value to it. If it is a 1 and all the other dice are also 1's, then you have a critical failure. That means that you have a 1/36 chance of a critical failure when your attribute is a 2, but a 1/216 chance if your attribute is a 3. With a target number of 15 being "impossible" you actually have a much greater chance of doing something impossibly well in this game versus doing something incredibly badly.
Furthermore, from a statistical standpoint having 3d6 to roll versus 2d6 seems to provide a pretty substantial advantage that has most of the target numbers for the game in single digits. With "5" being a common maximum value for stats, I guess it makes sense, but once again it is one of those games that seems to have interesting curves in its probability charts.
Like people have been saying about pretty much every iteration of Star Trek, the game does suffer from the odd convention regarding phasers. In the sole man-to-man combat of the game one player beat everyone else's initiative roll, drew her phaser and said "wide dispersal pattern, heavy stun!" That dropped all of the opponents in a single shot. For prospective Star Trek GM's, you may want to just set aside any notion of protracted gun battles, at least on a personal scale. Ship-to-ship combat, on the other hand, could go multiple rounds and was pretty engaging as all the PC's had a particular role to play during the battle.
It terms of roleplaying, it was head-and-shoulders above anything we've done in 4th Edition for a while, but despite this the group said that they wanted to go back to D&D on the next gaming session. It might serve as a palate cleanser, though, should the need arise again.