Interestingly the Obrera uses the same motor as on our Wisper Torque series, it's a great bit of kit.
For the new Wolverine Carbon fully loaded with Di2, we chose the slightly heavier Fazua mid drive motor, we figured that as the assistance was to be used on steep inclines, putting the power through the gears was more appropriate. At 13.7kg it is heavier but we think it's worth it, the other advantage is we can remove the battery and motor in under 1 minute to create a very light weight road bike.
Just finished building the first one this morning, ready for Eurobike. Studio shots to follow!
All the best, David