I pre-ordered my B21 via the Indiegogo campaign, and have been very pleased with my purchase. The Bluetooth handoff between multiple devices (Win 10 and Android) has been working flawlessly for me, and the battery life without backlight seems to exceed the specifications (perhaps because of aggressive built-in power management - it takes a single keystroke to wake from sleep, so don't expect the keyboard to detect input immediately if you've been AFK for 10+ minutes).
Were there some hiccups with my order? Yes, absolutely. The pandemic disrupted production and US inventory ended up in limbo at a California port due to problems outside of EPOMAKERs control. However, communication from the manufacturer was prompt and my keyboard was shipped express at no added cost once it arrived at the distribution center.
I will say that I was a bit frustrated with my missing braided cable, and have been exchanging emails with Peter for several months to figure out where my parts order was and why it was missing. However, this was recently resolved in a professional manner. A lot of things "went wrong" with my order, all of which were outside of EPOMAKER's control. I can't fault them for that, and I'm impressed by their service recoveries.
Final note: I'm not into modding keyboards and purchased this unit in hopes of finding a wireless workhorse. The B21 does the job and does it well!
PS - Where can I find quality keycaps with clear characters? It would be nice to maximize the effect of my backlight! Also, replacement knobs in different colors?