Why do you say that about the mid drive?
Jerky torque in the lower gears; crunchy gear-changing, especially when going up hills or caught stopped in too high a gear; the need to be always in the right gear; chain-line problems cause chain to come off; noise; reliability issues.
None of these things are bad enough to be a deal-breaker, but they all add up to give a less satisfying riding experience. I can remember when I first fitted a 500w crank-motor. I thought it was great for the first half hour as I powered through each gear like a racing motorbike, but in the depths of winter with cold hands, all that gear shifting started to become very tedious.
For me, the only real advantages of a crank-drive are for off-road cycling, where the lack of mass in the wheels allows the suspension to work properly and the central mass gives better response to changes in direction, plus you can get more torque for very steep climbs that you don't find on the road. On the road, a CD could still be useful if you wanted ultimate speed from low power, because a CD can still give max power at any speed, depending on gearing. That could be what you want with a road bike conversion, but for touring, commuting and generally riding around, the correct choice of hub-motor can give you all the speed and power you want and it'll deliver its power in a much more user-friendly way.
Mid drive with downtube battery will certainly be more balanced than what you have at present. If you are going for a Bafang unit, make sure you get the improved B version. Lots of sellers still knocking out the older model slightly cheaper.
