So if im hearing you guys correct - there's nothing wrong with the bike i've picked, but everyone is different and there may be something about it that I personally dont get on with. That makes sense to some degree, but can it really be that bad?
Do you get to test ride for hours?
Not having cycled for so long, what I found as a lifelong quite keen cyclist might not be such an issue for you, but it was the nature of the power assistance that I found a deciding issue.
E-bikes basically fall into two camps, a powered bike or a power assisted bike.
The former can near totally power you along requiring at the most a token contribution on the pedals.
The power assist is an enhancement to true push bike cycling, lending a welcome hand to the effort you put into it. I am firmly in this camp, I want to continue "cycling" as I enjoy "cycling" though nearing eighty I want a bit of help doing what I always have done.
In that the power management, even of the power assisted bikes differ and IMO that is an area where comparing different "takes" on power management contribute to decision making. How seamlessly power is added and removed passing through 16 mph.
Re time of a demo, the dealers I went to all I expect had an assumption I would not be off for half a day, if I recall, I probably was out for 45 minutes a time and no one took exception, at least evidently. They did require the test to be pre arranged.
What I would do now and I suggest is worthwhile, is to hire one that is at least similar to what you want, for half or a whole day.
I would suggest you discipline yourself not to buy your first "ride" there and then, all will impress. What I would need to know is this one more or less "impressive" than the others I have tried.