My years with those phones..
I had various BV-devices (BV6000, 8000, 9700 Pro, BL6000). The devices are robust and fast, but the software-support doesn't last very long which makes it insecure after a while (which is sad, as the device itself can be used longer). At least for security-updates i would expect longer support. Also a lot of my devices needed a longer USB-C-connector to be charged. This special condition can be annoying for a lot of devices which would work with android. Also, the metal-usb-c-cables in Blackviews shop doesn't work for some phones (yet only checked for BV9700, for that one it's too short). I think it would be a good idea to mention this. However, to remain fair, this has been resolved with my last phone (BL6000) which works with completly default cables. The answers for questions in the forum (bbs.blackview.hk) from BlackviewAdmin seems to be randomly distributed and sometimes topics are ignored but often answered. Via email i also got a response after i wrote a pretty angry mail. So, can may be better, but worked for me. All in all, there's potential to improve, but the phone i had before (Cat B15Q) was even worse in software-support and had definently a worse price/what-you-get-proportion. Yet i'm happy enough with BV.