My e-bike journey so far has been varied.
I started with a Woosh Sirocco CDL that I bought, almost as new, from eBay. Sorry to say that it basically fell apart under me*. Next I moved on to converting a couple of bikes I already had in my collection with FWD systems. Neither of these were particularly inspiring and I really didn't like the Heath Robinson look of the wiring.
Then an Oxygen eMate came on the market in the classifieds section here. After my previous experiences it was a revelation, BUT I had constant issues with the electrics. It's currently sitting, defunct, in my garage needing a complete new electrical system. If I had the time, inclination and budget, I'd fit a 48V power supply on it and sell it on.
Next, whilst scouring eBay, I found an Ortler Wien and bought it from a chap in That London. As soon as I got on it, I realised what I had been missing in terms of sophistication. Instant feed-in of power and a smooth delivery. I rode the Oxygen once after I bought the Ortler, even though the latter is a slower machine.
I was very happy with the Ortler, but then my current Cube was put on the market on here earlier this year and I quickly snapped it up. It has the Bosch CX Performance drive, compared to the Ortler's Active Line. The battery is also a Powerpack 500, so it has the capacity to make use of the unfettered CX motor. I would not even look at any other drive set up other than a mid-drive machine now. The Cube is very powerful, superbly put together and is everything I was looking for in a bike.
*Woosh seem to have upped their game with their later machines, but my experience of the Sirocco CDL was not good, although the company was helpful.