My personal used powertap SL+ Generation 2. Great unit. Has never given me any issues. I have it laced to a Velocity A23. I used it on the road as well as off road briefly. I laced it asymmetrically. The non drive side is 3 cross while the drive side is 1x. Also all drive side heads are in. If running a 23 cassette you could end up with your derail rubbing the spokes but I used it mainly with 25 and larger and had no issues.
I believe it is currently set up as a 10 speed but can be converted to 11 by purchasing a freehub driver.