I dislike the Michelins due to the fact that I had like 2-3 punctures in like 1000 miles or so.....but other than that, they are fine. They are ok for racing, not so much for training I have found. My favorite training tire of choice is actually the Bontrager Race Lite Harcase tires. You can run pretty much anything over with those things and not get a flat.
When I had the GP4000's, I dunno.....kinda felt like my tires were stuck to the pavement. It was weird. Between that and the fact they were a mother****er to mount.....I just wasn't happy with them.