As much as I love Haken and their work, the body of work that Steven Wilson has put out has been superb, and I never really disliked any of his albums as they came out, but with Haken, it took some getting used to with albums like The Mountain and Vector.
It's pretty close, though, and depending on what they both do next, I might prefer one over the other. To be honest, though, I haven't listened to any of SW's solo albums in a VERY long time, but I do recall the feelings they give me as I listened to them. I eagerly await his next album as I really enjoyed To The Bone!
-Marc.