My instructor (Maggie Casey) told us her favorite wheels were Schacht, and that they were "a little finicky, like all fine wheels" but well worth the slight fussiness.
Nicolassa, are you in Boulder too? After I learned to spin on my own, I took Spinning 1 and 2 to pick Maggie's brains. She's the best. I still call her up with oddball questions such as, "What is the best way to spin yak down?".
I had a Lendrum DT and just recently was thinking of upgrading to a Schacht, but just didn't want to deal with the maintenance (too lazy to oil), so I purchased a Majacraft Alpaca. It's presently on it's way to me now, so I can't comment on it. Although it is not a double drive, sorry for going off topic.