Class 3 rear hub, no throttle. Five levels of assist (1 minimum, 5 maximum, 0 = off.)
When I got the bike nearly 2 years ago now, I was out of shape & overweight and hadn't been on a bike in 25 years. I used a lot of Level 3, 4, 2 in that order of frequency. Level 5 is great for a quick thrill, it is like Superman pushing the bike from behind, but is way too fast/too assisted for my typical kinds of, and locations for riding.
As I biked more and more (and more -- the beauty of ebikes -- by eliminating the painful reentry process into biking, as an out of shape person, it left only the fun of biking, luring me into wanting more riding every day!) -- then I settled into Level 2 mostly, and began shifting gears more regularly. (I wanted exercise results from my rides, not just pure "Sunday leisure cruising" all the time.) Eventually I finally settled into Level 1 almost 100% of the time... that's where I ride most of my rides today, popping into Level 2 when there is an incline and I don't feel like heavily exerting myself, or I don't want to lose a lot of speed. (*Speed being a relative term -- while I generally ride actively in the 15-18mph range on flats, my overall lifetime average speed of all rides combined is about 13mph; though I believe this includes factoring in trip time spent stopped at stoplights, stop signs, etc, for example.)