I just dealt with the whole x-station thing a few days ago. As long as it is hooked up right you shouldn't have any trouble with the audio side of it. Pretty staightforward, just select it as your core audio device.
As far as the control section goes let me just say- it is a brilliant controller for Ableton and Reason. I love it to death and don't know how I lived without it. Logic is a totally different story. The problem is really two fold. First, Logic will not recognize the x-station in the control surface window (like a mackie control or other) Second, its instruments respond to a special type of MIDI like data called "fader" data, making it difficult to control the program with a generic control surface. While there is no direct fix as of now (a Logic control surface profile would solve this in .03 seconds), there are 2 workarounds. The first is offered by novation as a download and it consists of a template for the x-station and a special autoload that will allow the x-station to control Logic like a mini mixer type thing (ie: Faders, pans, solos). I have not tried this as my autoload environment is so complicated as it is. I decided I could live without the transport buttons and faders for now. But I refused to let my ES2's and EXS24's not benefit from this sick controller.
My solution was to just split the data of the x-station before it gets to the sequencer input. One path goes straight to the sequencer (for MIDI) and the other goes through a set of transformers to convert the CC to Fader data. There are problems with this though because Logic has the instruments mapped out all wierd. For instance on the ES2, the "tune" parameter is mapped to Fader data # 1, so when you convert your CC 1 (modulation!) your mod wheel tunes your ES2! The fix was to just put another transformer inline and reconvert only fader 1 to CC 1. It might sound like a pain (it is) but once its set up, its set up. The preset templates just have to be tweaked a little to work with each audio instrument, for some reason not all the controls are utilized properly.
If you really want to see something cool check out the new novation ReMote 25 SL! This thing can automap temeplates based on what track you have selected on the arrange. Truly amazing if it does what they say.
G5 dual 2.0 Mac OS X (10.4.3)
G5 dual 2.0 Mac OS X (10.4.3)