I have had a couple of scooters. One was a Sharper Image CityBug that I resurrected from a junk heap at the side of the highway. I put a 36v battery and a brushed rear hub motor on it. The tire is solid. It worked well to go around the block. Though, with a solid tire, I felt each bump. I had to make sure my tongue was tucked away from my teeth. Solid tires are very jarRing. I highly recommend to stay away from tires like that. Now, there are solid tires that have, horizontal, holes in them that is supposed to help, but I’ve never tried them. A single motor was giving me trouble going up hill.
Now I have an Apollo Pro (2019). It has 52v battery, dual motors, dual suspension, and pneumatic tires. That rides like a dream. I love it. I live in a hilly area and this scooter has no issue going up hill. The scooter can do almost 40MPH, but I ride in ECO mode. That caps the speed to 15mph. I even go up hill at 14mph. For me, that is as fast as I’d like to go on such small tires.
For reference, the Apollo is about 80lbs and I’m 160lbs. The hill I’m talking about is short and starts at about 6% and quickly increases to 12%. If you have hills in your travels, I highly recommend dual motors.