Touring - Sturmey-Archer X-FDD Hub Dynamo

Have not been able to find any documentation on this particular dynamo. I am especially interested in the drag when both on and off. but any experience with this dynamo would be useful information.

Thank you.

I'm new to dynamos, but laced up a wheel around the shimano disc brake version last month. I've commuted a few hundred miles and love it. I know that's not what you asked, but in my case since the hub internals were based on an Ultegra, and my previous hub was a non-series shimano - the dynamo actually rolls smoother than my last hub.

IMHO - $75 at JensonUSA was well spent for the shimano hub. I briefly considering the SON, but at more than 3x the cost, couldn't justify the marginal improvement in resistance.

The current Shimano looks pretty good!

http://www.peterwhitecycles.com/Shimano3N70.asp (http://www.peterwhitecycles.com/Shimano3N70.asp)

All I know about it is that it includes an internal hub brake. I just bought a shimano dh 3n71 hub dynamo, but I considered the Sturmey, and I'm actually having a bit of buyer's remorse, despite the fact that I'm very happy with the shimano.

The reason I didn't buy the sturmey is that there is no available documentation on performance that I know of. But I've learned that Sanyo makes most of the internals for hub dynamos that are sold by all producers, except for Schmidt. I'd bet that the same Sanyo circuitry can be found in both Shimano and Sturmey Archer dynohubs. If my guess is correct, then the only real performance difference would be in how good the bearings are.

I did buy and lace up the Sturmey XFDD Dynamo Drum. Dynamo performance is similar to Shimano, and the drum brake is superior to a caliper brake. All in all, very satisfied.

Any more thoughts on how this thing has held up? Almost 2 years later,