I love the restraint in this piece. It's smooth, cool, and yet has some tension. The guitar is perfect.
I'm going to break with DJPretzel and say I don't think a "balls-to-the-wall" solo or improvisation would have benefited the piece any, but this is mostly due to a personal preference. Personally, I like precision in music. Make it emotional, make it *feel*, but at the same time make it precise and crafted. Improvisation and such may add a "human" touch, but to my ears that human touch always feels more like a flaw. I like some pieces that are heavily improvised, but on the whole I prefer pieces like this. Something with some underlying depth (love the drums and bass in here), a little passion (nice synth and guitar usage) and yet some precision in it's makeup. So to me, this piece is superb.
~Buster