I like the 121GW for Bluetooth, long battery life and you can backup/restore both the firmware & calibration. A recent firmware hack to disable mode selection memory is handy.
Selector switch is nice and light. You can adjust the display contrast. The secondary display can have a few goodies displayed: internal temperature, burden voltage, time, date, battery level. You can turn the beep on and off with a couple button presses.
However, I have not found the mA display via the A shunt to be particularly great, since the accuracy suffers. The BM869s can generally provide just as good mA values using the A range (1mA is no problem). Ultimately, I can get far better numbers from my high-end bench meters via the mV function.
It's absolutely true that UEi has never been at the same level as Brymen from a hardware performance perspective, but on the flip side Brymen is pretty well stuck in a rut. Their software is ancient, the BM78x series didn't really bring anything new to the table compared to the BM869s other than a slightly smaller form factor, NCV detection and AutoV/LoZ. They also play games like many other companies by limiting features to segment the products (handheld vs. clamp for example).
My main point: if you already have a BM869s on your bench, then why get the BM786? They both have poor battery life at about 100 hours and have a lot of overlap.
But otherwise it does what it says, no problem there. Although my early BM789 has a list of problems, such as beeper dies with the magnet attached and it makes a clicking noise when you turn it on. Luckily I dodged a couple other major issues before and after my revision number.
I stopped watching Joe's videos many years ago as I eventually realized few to none of his tests were of any interest to me. This was back when I also watched lots of shootout videos and bought what was recommended. I ended up with a bunch of equipment that I didn't like and had to go buy the equipment I really wanted.
The uCurrent Gold has been out of stock for quite some time from I've seen. I managed to snag one about 2 years ago, but use the much more expensive CurrentRanger instead due to the handy built-in display:
https://lowpowerlab.com/shop/product/152Again, a you may be surprised at what you can do via the mV range on your existing DMM...