Yup. I play it quite a bit. It is a streamlined version of Star Fleet Battles but it's still quite involved. It still has a lot of the ideas that were common to games designed in the early/mid 80s. There's a lot of book keeping involved and you'll be spending a lot of time filling in/out energy allocation points for your ships and crossing off damage boxes on ship diagrams. If you have played things like Battletech or Car Wars, you'll get the idea.
I prefer to play the game with miniatures but use the hex system instead of rulers (there are rules for both) but it works just fine with the counters. If you're just looking to get one set, I'd start with the Klingon Border and see if you like the game system. The rules governing the Federation and Klingon ships and weapons systems are fairly straightforward and you'll be able to pick up and play in a short time. The Romulans are a lot tougher to play and are far more unforgiving of mistakes. The rules governing them are more complex (cloaking and plasma torpedoes add a fair degree of complexity) and you'll need to be quite familiar with the timing of all the sub-phases in the game in order to play them effectively. They excel at ambush tactics but are very frail and just can't go toe to toe with Federation ships.
There are a lot of free supplements in the form of new ship cards, scenarios, campaigns, and special rules available for free from the Commander's Circle.
http://www.starfleetgames.com/federation/Commanders%20Circle/resources.shtmlThe licence that ADB has is a bit weird. From what I understand, their licence is based on a ship technical manual that was put out in the 70s so they can use stuff from the original series and the animated series, but that's it. You've got the Federation, the Klingons, the Romulans, the Gorn, the Tholians, and the Orions and the rest of the races are stuff they made themselves (except the Kizinti which are from another sci-fi series).
The game is a lot of fun IMO but the engine is showing its age and the rules do have some odd omissions. If you do get deep into it, I highly recommend getting the consolidated rulebook. Makes looking things up much easier than constantly flipping through several smaller rules supplements that you get with each expansion pack.
I'd avoid picking up the Tholians. The rules for Tholian webs are game killers. Slow the game down to a crawl and add way too much micro-management.
If you go the minis route, I recommend picking up some Heroclix ship minis. They can be had for $3-5 each and are regularly on sale from Cool Stuff Inc and Noble Knight.
Here are some of the ones I use:
Just a few of the charts and tables you'll need to familiarize yourself with.
Some shots from a scenario I ran at a con last year.