Ian...my wife has a Garry Fisher with a front hub Juicy Bike conversion, plus throttle, and it has been excellent...she now very rarely uses the throttle as the cadence sensor in the pedelec provides just enough extra oomph, BUT it is nothing like as user friendly as the Bosch torque sensor..
basically the 5 options on the remote thumb switch on the bars, are 0 assist, 30%, 100%, 150% or 250% or something like that...so whatever your input is, it is boosted by that amount, and it feels very different to the cadence sensor, which is just based on crank speed, eg the lower the gear the faster the motor works, so not much assist, or none, with longer gears
I have had it off road around the tracks of Alexander Palace in nth London, and there are some serious hills here, but with a bit of serious rider input, it goes anywhere....
I am still pretty keen to give it some welly myself, so usually stay away from the big inputs, and hang around the +30, or +100 at a pinch
.....unpowered it feels like an expensive mountain bike...........excellent
but as electrifyingcycles says, you have to have a go somewhere...although having said that, I ended up buying one with fingers X'd
cheers barryc.