For me, practical for a motorized bike means unlimited range. 20 years ago, I used to ride Puch and Tomos 50cc mopeds 300 miles at the time. A full tank of premix, and 2 more gallons in plastic oil jugs in bicycle panniers. I rode on the shoulders of rural country roads all over southern AZ.
I have an early '70s Solex 3800. It is quiet, but there is a huge fine for riding an internal combustion powered vehicle where I want to ride. Not worth getting caught. Besides, it is sometimes fairly crowded, and somebody would notice.
Yes I love the sound, feel, and smell of a 2 stroke engine.
CENTURION, yes, that is the kind of riding I'm talking about. Nice and slow, peaceful and relaxing. That's what I used to do on a pedal bike back when I could still pedal. I am considering the RadCity 5+ stepthrough. Yes, it's $2K, plus I would need to replace the seat with something more comfortable, and probably add a suspension seatpost. NOT cheap. That's why I'm taking so long to consider it.