X3 looks like a render movie. Imho it's the best looking game atm and might even be at the end of this year.
It has pretty nice music. Some track are awesome. The sounds are... ok and if you like trading, you'll love it.
The fight part is a bit sluggish though. X3 has some weird half-newtonian physics. They do make it feel more realistc sometimes, but are also annyoing pretty often.
The story isn't bad, but it's told ... somehow boring. The dialogs aren't very good. So are the render movies. They should have sticked to the great in-game graphics.
I like the fact that you can do pretty much everything you can think of. You can buy stations, hire freighters, buy large capital ships and join battles in your fighter and even exit your fighter and fly around in a space suit. (It's just cool to fly around your gigantic carrier in your space suit.
There are more events than in Freelancer. If you don't follow the story in Freelancer, you can't really do much. Nothing happens and picking up one of the three different missions isn't fun after running through a few of them. X3 has some way cooler missions and even some war events. (The Xenos attack a sector.)
It's not like Freespace!