Vancouver British Columbia has its own fair share of steep hills too -- we live very close to the mountains and some streets are very steep -- very close to 20% grades. If you ride your Bionx like an eZee or a straight throttled bike, then yes, it's a bit slow and underpowered. So, you must ride the Bionx like a regular bike. You must shift your gears down to granny at the 20% grades and my Dahon Mu SL is set up that way (therefore I loose my high speed gearing). Other than that, my low end low powered P-250 can take me up any steep long hill. In fact, I rode with regular cyclists on a Sunday ride for up to 65km assist with last 15km no assist to a total of 80km with 5 hills on a 24V 8aH NiMH batt (1 of them is like 4km long 8% grade) and the P-250 managed to outdo the hill climb with me riding against my best friend on his carbon bike. As you can all see on this equation, the system shines if put under a good fit rider. In fact, the fitter the rider, the better performance the system will get which actually makes you a fitter cyclist by riding it because you are still exerting pedal forces. You see, if you want to push the Bionx hard, you can and it will reply with much more forward propulsion. Just a few days ago, I was going up this steep 10% grade hill at 28km/h trying to match my speed with a 800w electric scooter which was going much faster so perhaps 32km/h. The best a strong bike racer on a carbon bike can do on this same hill is like 18km/h, while I can only do about 14km/h which if I multiply it by pedal ratio set by the computer yielded 28km/h, but the pedal effort can not always be constant and your power output varies and your crank spin varies too unless of course you're somebody like Lance Armstrong. So the Bionx system will fill in your power inconsistency and provide consistent sum of your and its own power output. Again, no system and no human being can do this to respond that quickly. It's simply impossible because you can't really know what your power output unless you strap a heart rate monitor all the time when you ride an ebike, which is kind of stupid or have a Cyclops Power Tap hub at the rear. And heart rate monitor is influenced by stress, heat, and your medical condition. In fact, that's the idea behind the Cyclops Power Tap hub -- to train a cyclist to manage pedal power output for efficiency. The Bionx's strain gauge works almost the same way. I know eZee has this potentiometer thing and yes you can dial it in and yes you can apply your own manual assist, but it only works in some gears. In the Bionx, the proportional assist works in ALL gears, that's all 27 speeds if you have a 9 speed cassette and a triple chain ring providing natural power assist to pedal power. This is what appeals to me more than any other powerful system out there and that is why I chose the P-250, because I wanted only the assist not a speed hare that can go 45-50km/h or up some 10% hill at 32 to 40km/h. If I want that, I drive my car which can go a lot faster, go further and have more room to carry my heavy work equipment. I know some people who came from a car culture and immediately wanted more speed, range etc, but they are forgetting that it is still a bicycle. The more you put into the bike to become faster, the more it becomes a full assist vehicle. It's like comparing my car to my Bionx bike is no comparison at all. They serve different needs.
There's really no great system out there, Bionx notwithstanding. The downside of the Bionx is truly its unique close system, though I've seen what's truly inside the battery box and the circuitry and I know you can adapt any battery into it but you must disable the regeneration function, or I suspect you might fry something. When my NiMH dies, I will do just that!
Last but not least is the cost of running the system. As NutsnVolts had pointed out, while the initial cost of setting up an ebike may not be much, through upgrades the cost will go up. If the ebike is your primary mode of transportation then the cost is justified. When an ebike is a suplementary mode of transportation like mine is, then the cost is factored into my future gas purchase. If I spent $1500 for a Bionx, it means $1500 of my gas money is gone into this bike. If I don't ride it, then it's trapped on that bike, so I figure that if I like riding it more, then I sure will save some money by driving less. There are stretches on my commute route that I wished to simply push that throttle button and pedal as fast as I could because of the vicious truck drivers who show no patience waiting for a cyclist to cruise through at 30km/h. That's where having the motor really shines.
