I've never met anyone that didn't like their GP4000's.
I imagine you combine them with an Ironman and you go cosmic.

Jim,

The Wolber Super Champion was a nice rim, but my favorite Ironman rim was the predecessor, the rounded Araya 20A in copper, for looks, anyway. I imagine the Super Champion was expensive, because the next year Centurion went back to the Araya, the CTL-370, named for the claimed weight of the rims. They probably should have called them CTL-380 to 388 on average.

I've got a set of Sansin sealed hubs laced to Matrix Titan S's. They're the closest thing to the CTL's, lighter in the hub, heavier on the rim. I saved them for a bud's Ironman build, and he decided his '87 Master needs his 600EX/Super Champions, instead.

The Ironman was notorious for the wheels going out of true. This was not due to the wheels, but most likely due to the 700x18 Panaracer Technova tires. They were hard as rocks. Two bike magazines tested the Ironman, and both threw out the tires after the initial rides.

The GP4000 rolls well and lasts well and is a tough tire, from what everyone tells me. I have riding friends who only ride them, no exception, on every bike,