I have just read your other post where you were considering converting your existing bike using a Bafang BBS
Based on your needs it maybe better to try one and play around with the cadence and see how it feels.
My main gripe with factory CD set ups is that I cannot attach a throttle, whereas to the Bafang CD or a hub I can.
I am with you on the quality of Shimano but it comes at a price, which we can debate in terms of value however it is not so much the price but the inflexibility of the system that precludes me from purchasing one.
I believe they have a new model the E8000 which looks slick on the youtube video have you watched it?