- Dual display that I've never had and so don't really know how useful it is. Comments have been made that I could just as easily add a second meter for the second parameter.
The dual display is super handy, especially to see for instance AC+DC and the AC component in one glance.
- Data logging is a feature I would really like. I've read however that Brymen data is really weird, so I'm wondering if I'll be able to get it working on a Linux machine without having to write software myself.
Besides the brymen software (which is not that good), there are at least 2 free 3rd party programs that can log from the BM867/869:
TSDMMVIEWER:
https://www.ts-software-jp.net/index.html(I think I use this one the most)
and Testcontroller (lot of functions):
https://www.eevblog.com/forum/testgear/program-that-can-log-from-many-multimeters/Afaik both can log at 5x/sec in high resolution mode (500k counts) despite the brymen manual saying that update rate is only 1x/sec in 500k mode.
The only thing imho missing on the BM867/869 (and also on the bm235) is a good autohold function. And the 9V battery is...meh, but acceptable.
For that the BM786/789 is a good alternative as it has a very good autohold, but that has no dual display, no 500k high resolution mode and no logging/pc interface. Especially no logging possibility is I think a missed oppertunity in this day and age for a high spec meter. They gave the BM867/869 that functionality, and they are more or less the same price, so why not in the 78x series?!?