Bikenut I'll preface my comment with a statement of fact. I'm a newcomer to e-bikes though I own four and built three. That said mid-drives are fine but the hype is pure marketing. I think they look fine, but don't see them any more or less attractive than wheel hubs as a design selling point, if they produced more power I'd be impressed but they don't, if less expensive relative to power I'd be impressed but they cost a lot more. If they are higher quality and deserving of the price differential I've seen only superlatives not as a result of objective testing by qualified & uninvolved third party labs.
Pretty marketing in words and photos are nice yet drive up the price. Mid-drives made in China are somehow better in quality than hubs made in the same country. Low center of gravity sounds really impressive as does "central weight distribution" to a dedicated racer, but the average e-rider shouldn't give a crap about let alone pay for something so silly.
Hubs ride low and you if want better balance add batteries up front. Have a front hub run the batteries on back. If you want to really lower the center of gravity and offset the added weight of all e-bike components; it's cheap but not so easy to do, just lose 30 or 40 lbs. off your mid-section and lay off those gummy bears. Don't want to drop your body weight the old fashion way then buy a dropper post to lower center of gravity in corners and raise the post for correct leg extension pedaling on the straights. If the mid-drive was easier to install than e-hubs I'd think that swell but they aren't and they still cost far too much. My last thought; if you break a chain on the mid-drive you paid a lot extra for the right of pushing her home. You can admire the so called elegant look as you lose weight pushing her home. Bottom line they aren't all that!
I still enjoy the beautiful builds using mid-drives.
Rick C.