The Kalkhoff will give you up to 130% of your torque. You will not be able to speed up this sort of grade as if it were flat, but if you could do it before, you will be able to do it faster.
I bought my Pro Connect Sport 250 last week, and it arrived last Thursday.
I have a 5% grade hill that's almost half a mile long on my way to work. Today, I didn't feel like slowing down so I kicked the assist on high and pedalled a little harder. I climbed it at about 20 mph. I can climb a 7% grade hill without effort at ~12 mph. I'm not sure where to find a road around here that's 20% grade, though. If you find a steeper hill within 10 miles of Provo/Orem, let me know and I'll give it a shot.
I compared my Kalkhoff to a Trek FX+ on that same 7% grade, and I found that the BionX did have more oomph (14 mph with no effort). This is because I had the BionX on 300% assist vs. the 130% assist.
I really like the torque-based pedal assist, and the only hub system that comes with it is BionX. I've not tried to max out the assist systems.
Panasonic-based systems like the Kalkhoff won't give you a free ride, but they will make it a whole lot easier. If you find a hill with a higher grade you want me to try within 10 miles of Orem or Provo, I'll let you know how it goes.
Kalkhoff does have the 7-day refund period after you get the bike, so you could demo it. I don't know if you would have to pay shipping for the return if it wasn't good enough.