I've been a fan of X3 for years, and bought Rebirth (long after it received several major patches) knowing that it wasn't "X4". What I didn't know was that it uses a totally different user interface and control system, and that doesn't work on my PC. The controls are pretty close to "on" or "off", which means the Skunk is either sitting motionless or racing at full speed (although if I fiddle with it back and forth, I can sometimes get it to some intermediate speed), and any course changes are in the 20-40 degree range or greater, or else nothing. I can spin the ship in circles without really trying, but a 5 degree course correction takes a dozen swings back and forth.
After more than a half hour of trying to land, I managed to crash more-or-less intact onto that first repair base you're directed to, but once again, walking around was either "stop" or "run full speed", and turns were extreme or nothing.
I'm using a common Logitech mouse and standard keyboard, and it didn't function any differently with a different mouse or keyboard. Basically, the game's not compatible with my system, and Egosoft had no suggestions that made any difference. Other players don't seem to have the problem, but be aware that it can happen. The rating is kind-of arbitrary, since it's difficult to rate something that you can't run for some odd reason, but which looks like it SHOULD be decent.
Since I believe Egosoft uses the same control interface for X4, I'm not about to sink money into that. Pity, because I loved their earlier games.