Had been waiting for this "bullet- proof" Powertap hub with DT Swiss internals for sometime now as have been totally satisfied with all my previous and current DT Swiss hubs. Purchased in Oct., built it up with a Reynolds Assault 40 C/F rim and put approximately 3000 miles of hard riding on it in 3 months. Everything worked flawlessly until a screeching / grinding sound began under heavy torque - much like a BB issue. After servicing the Campy U/T BB cups and removing / cleaning the cassette to no avail, it was traced to a dirty / dry internal free-hub body that would not let the pawls engage sufficiently. After cleaning and lubing, it works perfectly again. I think DT Swiss is notorious for not lubing their F/H bodies sufficiently coming out of the factory I will of course, monitor its long-term performance.
April 2016 Update: I've had to replace the electronics ring twice. Last year (with about 10, 000 miles on the hub) the calibration went awry and Saris replaced the ring. Then within the last month I started to get a battery drain and it was replaced free of charge again. Other than these minor inconveniences, I like the hub (and BTW, the price keeps coming down!)