I'm a big fan of the Evelo/Gates Belt/Enviolo drive system, which is not all that common in the ebike market (yet). But they do command a much higher price. The Aurora Sport (Limited SL??) with the chain drive, derailleur, and hub drive puts it into a VERY crowded market with a lot of other good choices. They have reduced the price to $1,700 but there are many ebikes out there in that price range. I noticed that the Aurora Sport has cable operated disk brakes which is not great at that price range. Evelo's service/support is at the top of the chart, but looking at something like the Aventon Level Step Thru at $1,500, it would be a tough choice.
The Aurora Limited SL is an Aurora Limited customer return that has had the belt removed and replaced with a chain, and the shifter replaced with a manual shifter.
I guess I'm wondering how well the chain will hold up with a high torque mid motor.
Ah-ha, I didn't realize Evelo had modified some of their returns! I wouldn't have any concerns about the chain strength. The majority of mid drive ebikes on the market are still using chain and derailleurs. I have the Atlas with the manually shifted Enviolo hub (same as the SL) and it works well. Although it does use a twin 'push-pull' cable system all the way from the handlebar to the rear hub.
My previous Aurora was a nice bike and I really liked the (discontinued) Enviolo Harmony shifter.
I just bought an Aurora SL and it should hopefully arrive in a week or so. This will be my first e-bike and I think it'll be a great fit for me. I wanted an Atlas and could probably swing an Aurora Limited. I figured the SL with all the benefits of the Limited but with a standard chain drive and manual shifting should be a fantastic introduction to e-bikes.