Bought a 2nd one so I could have 2 batteries and replacement parts in case something happens after the warranty expires. I have put on 1,000 miles so far and still recommend to everyone who asks and love it!

As for the review underneath me:
1. You don't have to stop the bike to adjust levels, just stop pedaling while rolling and get to the assist you want. (up/dwn would be nice though and more levels. It jumps from 15mph lvl3 to 23mph lvl 4)
2. Should take no more than 2 hours to assemble. It isn't that hard, just youtube https://www.youtube.com/watch?v=_ZQuxTqMEkI&t=67s is the best one.
3. Yes when you go uphill the battery level goes down and then back up. A bigger bar or maybe a voltage meter would nice but test different levels and figure out your range// a new display will not help your issue, that's what all bikes do: Pedal assist 3 (15mph) for me gets at least 45miles. at 3 bars it goes down to 14mph then 13mph etc
4. You're going to have to do some minor adjustments to stop that squeak on the front pads. (also you tube or bring it to bike shop) I got mine to go away. keep the pads though you may need them later as they will wear out.

It have so very minor things but for $899 it is the best and cheapest with all the other options.

Awesome bike , very strong motor , easy to assemble, very well built bicycle with excellent components, excellent price , great value,, delivered free and it arrived immediately, took 3 days from when I ordered the bike , this is a strong very well built electric bicycle,

After 2 months of research on all the e-bikes, the S3 has everything you want and need. Folding feature for easy portability and storage. Free shipping and no taxes!! 25mph throttle will get you 25miles (go slower and get more range using peddle assist). 750w motor is powerful. 20ah Batt has impressive range. 3inch tires are perfect, not bulky 4inchers. Step-thru model is easy for mount/dismounting. Folding seat to get the battery out easily (comfortable, no need to replace). Taillight and Brake light! Front light is impressive. Front shocks do a great job. Mechanical brakes are fine and easier to fix than hydro's if the ever break. Compact display has what you need to know. Back rack is great. Plastic fenders don't rattle like other metal ones.

only cons:
~a spare 20ah battery is listed at $590 at this time. That is way Way too much. I may as well buy another bike for spare parts :( Also I don't see a charger coming with it or even one to buy in their store.
~screw holes for a water bottle holder on the neck would be nice.
~Battery rattles, but just put a cloth where it sits on the frame.
~Battery charge time from empty takes almost 11hours for me.

At 73 I purchased a step-thru S3 bike to exercise for my 2 bad knees. I do good on level and slight uphill grade, when my knees start to hurt or going uphill, I just hit the pedal assist and away I go. After riding just 1 day, I purchased a S3 for my wife also. It works good on our gravel road and plan to use camping. Great bike!

It's a fun and fast bike!