Bicycle Mechanics - How are Ultegra 6600 hubs?

I'm building up wheels with velocity rims, and I want some DURABLE hubs to go with them. On Craigslist, I found both HB-6600 and FH-6600 for $100 (That's both hubs for 100, not a hundred each). I can't seem to find information anywhere on the FH-6600. There are plenty of reviews for the FH-6500, but few (if any) for the FH-6600. What do you guys have to say about these hubs?

The 6600's are the current "10-speed" hubs. If there are any differences between it and the earlier 9-speed (6500) and 8-speed (6400) hubs they are trivial. BTW, Shimano's web site had all the info on these hubs. Here is the link to the rear (FH6600) hub:

http://bike.shimano.com/catalog/cycle/products/component.jsp?PRODUCT%3C%3Eprd_id=845524441770451&FOLDER%3C%3Efolder_id=2534374302053472&ASSORTMENT%3C%3East_id=1408474395181785&bmUID=1199468846849

Shimano hubs have a deservedly very good reputation. I have a set of Dura Ace (7700, 9-speed era) hubs with 40,000 miles and all of the parts except the bearing balls are original.

They're great hubs. I like mine a lot -- been riding them for 2 years now, and they're smooth as silk on a 6 month maintenance schedule. The big difference with the 6500 is that the 6600 has large diameter hub shells, which does make the flanges more rigid. I don't think this translates into anything you'll feel through the bars, saddle, or pedals though. It's mostly just an updated look.

Great hubs, and if you take care of them, your great grandkids will be riding them.

I have a set of the 6600's on my training wheels and have been putting about 300-400 km a week on them for two years and have not had a single problem with them. Considering the small weight difference between Ultegra and Dura Ace unless you are planning to do up a set of lightweight racing wheels I would grab them.