I am still toying with which kit to put on my Trek 6000. I am torn between the Daahub and the Bionx. I know the cost of the Bionx is high and but it does seem to be reliable and have a good reputation on reliability. My route is predominantly up hill one way and then a series of steep down hill sections on the homeward route. I test road a Bionx and did like the engine braking effect and it was certainly powerful uphill. If I go for the Bionx I would love the latest 48v version but at £1799.00 it is very pricey. If you look at the 50 cycles Bionx it makes £1995 look cheap. At the other end of the scale the lightweight 250S might do the job balancing weight over power. The Daahub certainly seems like it would fit the bill and Eddies posts to date sing its praises. No engine braking but it would have the Wisper support. Hard choices.