I have take a quick look of those documents, the information on them worth's something if they are fresh enough, the first one looks outdated.
Secondly not all manufacturers haves the same advanced technology about their offerings in OLED's.
The first document talks about 5000 hours life-spam, when the latest high quality ones does 100K hours.
About the one time reviews ... I like to believe that I am making the difference.
And actually I am teaching of how the proper reviews should be made.
It is not my intention to drive this conversation in to an off topic personal rant about what others do.
But my reviews does not contain a simple "take it apart" and few tests with DC volts and resistors.
No one except me had ever publish VFD filter performance tests of multimeters, or even frequency tests, or even present combination's of advanced functionality as I do.
Or even the use of external accessories like the hall effect curent probes.
The quality level of the ITTSB reviews is the highest ever at list about multimeters.
And about the user interface of its multimeter, I have never discovered a bug in the software.
But some personal likes and dislikes could come from what you had use to using in the past.
I love the Olympus digital cameras menus, if you give me a Nikon I will just kick it out of the window no matter if it cost 5000 EUR.
Their menu system sucks big time.
I do agree with your saying "You grow in your DMM", but very few do that, most of the people they trash the User Guide with out even reading it.
Can you possibly imagine that I do read the most portion of the User Guide of its multimeter that comes for review ? and how difficult is for one single brain to hold this amount of information ?
If you ever nag again about your two multimeters, I will send you seven for review so to make your head to explode.