Yeah I use a VS-100 with SPlat. I was just using it to select the track I wanted and arm record, then start recording.
In SPlat you set it up pretty much like you do in X3. I have both on my system and it looks to be the same.
But I do remember when SPlat first came out it had some "problems loosing the setting" so to say. And you had to reset them all the time. But that was fixed. I haven't had a problem with my VS-100 in a while.
I am on Win7 64.