I havent used them but theyre easily the most ridden hub in Tokyo. Damn near every bike you see has these or Dura Ace.
As Ceya pointed out at one time, these hubs are made off of the design of Suzue/Sansin/Suntour/Sunshine NJS hubs. Which were all basically the same hub.
Ive compared a set of these with my Sansin NJS hubs and they really identical except for the fact that the GranCompes are sealed and come in about 7 wacky colors.
If anyone thought theyre were like Formula hub then theyve probably not held a set before.