I ordered a halfbike online, with a 30 days trial period. The package weighted a lot less than I expected (nice!) and the construction was do-able with the instruction-video (but why they have a different order of construction-steps in the video vs the manual puzzles me).
I've tried the halfbike in several sessions, but couldn't manage it. I find the handlebar too narrow/not wide enough and I didn't manage to withhold my reflex to dismount the bike if I was out of balance.
So even after an extended trial period I had to conclude that riding a halfbike wasn't for me. Too bad, because I think it would have been a great workout and I was looking forward to riding it in the woods and the dunes.