You might have gotten a 'dog' with the particular ebike you tested, might be worth trying a couple of other shops and different bikes and see how they perform?
You also might need to manage expectations, if you want the wow factor you need a way more powerful motor, controller and battery. Depending on your point of view re the law where you are that's a decision to be made, buy anaemic ready made stock legal bike or use donor bike and conversion kit for some fun.
A 1500W rear hub with a 17A continuous/35A max current controller will draw almost 1800W peak according to my KT-LCD8H using 52V battery, more than enough to send you on your way at 30+mph.
I tend to drive on main roads at maybe 20mph using cruise control, 25mph on major roads,and I still smile.