Most free jazz-cum-rock experiments tend to start out intense and build from there, but these guys exercise admirable restraint, the leader most of all. In fact, West has dynamics like a classical recording, meaning that during the quiet passages that open each piece, you might make the mistake (as I did) of thinking that the record's over. But it's not. The guitarists employ clean tones, altered with just a little bit of amp tremelo, and provide beds of rolling chords for Hobbs to extemporize over. There's a moment when they set up a field of droning feedback for him to play off, but to everyone's credit, he doesn't try to play over them, and they don't up the intensity beyond what a supporting role requires.
I wouldn't exactly call this "mellow," but it's become the music I like to listen to when I'm trying to tune out distractions and wind down at the end of the day. There's definitely a dialogue taking place on West, but it's not one that you'll hear if you're not attending closely. A most welcome surprise.