I had the same experience when I got to test my friends' i3. I don't get why the regen needs to be so aggressive by default that lifting your foot off the gas is like hitting the brakes. Can't they make the brake pedal activate the regen (first, before activating the wheel brakes)? Of course, one pedal driving would be simpler if/when you get used to it. I didn't have enough time to see if I could actually like it.I test-drove the late, great i3 a few times back in the day, but the salesfools at BMW never explained the concept of one-pedal driving.
Lifting off the pedal to coast, but getting aggressive regen instead, sucked.