I've been down a few rabbit holes this morning. As promised here is a bit more detailed data of my Libre 2 vs Libre 2 Plus comparison. A few quick observations / conclusions:
1. This is not a very scientific comparison as based only on a handful of observations, so don't base any critical decisions on this
2. Assuming my glucometer and test strips (Freestyle 2 reader + Optium test strips) provide a good reference I'm not hitting advertised levels of precision (MARD, but this is not the only precision metric that can be used). It is important to note that glucometers come with their own errors and there are many reasons why CGM can be less precise in the wild. How and where the sensor was attached, how long I've worn it, time of day, how quickly my BG levels are changing, and the list goes on... But none of this means that CGM is not useful - the patterns and trends I observed via CGM and glucometer are generally aligned and in fact can be spot on.
3. Another conclusion I arrived at was that while newer generations of Libre are getting more precise, the actual improvement is negligible and given other real-world influences on your readings as per above probably won't make that much of practical difference. So my improvement in precision between Libre 2 and Libre 2 Plus most likely driven by other factors than improved precision per se.
I'll stop rambling and maybe one day do a more considered write up.