20" wheels with 2" tires do feel slow to pedal if the gearing is slow. I believe our Schwinn Loop came with a 38T spinning a 14T rear. Quite a slow bike to pedal, in my opinion. I don't believe I ever rode the 38T with a motor, but upgraded to 52T as part of the motorization process. A 260 rpm hubmotor can outpace a 48T/14T unless you're a strong pedaler. I put a 52T on that Schwinn,
My 20" folders top out around 20 mph on 36V, but we don't go faster than 15 mph unless coasting downhill. Slow speed urban riding. For faster riding, I'll use bigger wheels, The ride is better, Still over 2/3 of my miles are on the little wheels. They're nice for pedal assist because you've got the smaller diameter wheel acting like a lower gear. The smaller tires have less weight and spin up easy. I suppose the handling is more darty, but I'm used to it. The one tradeoff is they smaller tires won't span low spots like a bigger tire, and make bumpy surfaces even bumpier.