As someone who has owned both a
Turbo Vado 4.0 and a
Turbo Vado SL 4.0, I can tell you that if what you want is a pickup truck that can climb some serious hills, the the Turbo Vado is the ticket. It has a powerful and torquey motor and one can easily lower the gearing to give more climbing power if that is what you want.
The turbo Vado SL is much more a road bike with a boost.
I understand your desires. I am 74, I live at 5300 feet, and the hill up to my home from downtown Medellin has 2 short pitches that measure out at just over 15.5 degrees or 27.5% if my math conversion is correct. In either case they are kneebusters for an old fart like me.
I used to climb up the hill in my 2nd lowest gear with the boost on turbo with my Turbo Vado. The Turbo Vado SL has lower gearing than the Turbo Vado, but not nearly as much torque. On the SL I make it up those pitches in my lowest gear with max boost.
I am planning to swap the 40t cw on the SL for a 36 as Stefan SL advised me for a little more climbing power. Top end is no concern to me.
the Turbo Vado was a fine machine, but I have been a lifelong road/gravel cyclist and I don’t care for shock absorbers, suspension seatposts, and 58mm wide tires and 30+ kg of weight.
The SL scratches my itch quite nicely. As soon as I get the smaller chainwheel and the range extender battery I will be in hog heaven!