I purchased my first HB (HB2) back in Spring of 2020. As I recall I was shopping for a new bike but could not find one anywhere due to the whole covid thing. My wife (bless her) found the Halfbike website and suggested I just take a chance, which I did. Anyway, after a tough learning curve and some apprehension I mastered the riding technique and now am a lifelong HB fan. I ride for about an hour nearly every day after work when weather permits and don't do gym cardio anymore. I can feel and see the physical benefits of my riding routine. The riding sensation reminds me somewhat of skateboarding or snowboarding. My HB2 has gotten pretty battered so I upgraded to an HB3 early this year. It is a more refined product but also a bit more demanding in terms of balance due to some slight dimensional changes. Regardless, it is a fun, satisfying, and unique product.
--> HB company please read this: The week point are the grips. The stock grips are not substantial enough. I sliced them off immediately and installed larger, thicker horned grips (easy and cheap to buy) and it makes all the difference in control. A premium product like HB should come with better grips. Another issue, albeit small, is the weak adhesive used to fix the cable stays to the frame. Hot weather melts it and the stays detach. They are fixed to the cable, but still.
Anyway, I love my HB and I'd say it is one of there best fitness/leisure/fun purchases I've ever made.