i just got them a couple of weeks ago to use as race wheels. i've done one test ride on them and they felt pretty awesome compared to my current wheels, which are mavic ksyrium elites. to address one of your points, they are NOT internal nipples; i think they used to be, but at least on this model they've changed that.

FYI, these are planet x R50 tubular team edition wheels. they're 50mm deep and the claimed weight is 1296g. i've never weighed them but they feel really light.

as i said, though, i've only done one ride on them. i can give you more feedback in the spring once i start racing on them...