I've been a fan ever since In It For The Money
came out. What a fantastic album, from beginning to end! Mick's playing has always been pretty solid, and he always impressed me with his taste and restraint in what was essentially a power trio (at least at the start).
As for basses? IIRC, he's been playing Ibanez Roadstars for quite some time. Essentially, it's a P-Bass copy. Funny though, I have a strong recollection of seeing Supergrass play "St. Petersburg" live on one of the late night shows, and for the life of me I can't remember what bass he was playing on that appearance. But in the video he's actually playing what looks like a Gibson EB-3.
Mick's actually on Twitter, too
. He doesn't talk bass so much though, but he is fairly active.