Just put some in my basement fixtures. Tried the 5000k but they were… just wrong. Too harsh. The 3000k rated ones (which feel more like 4000k to me) are quite nice, though. While not ULTRA high CRI, they are very decent and certainly heads and tails above most other commonly available LED or CFL bulbs. Typically our basement bulbs last a long time due to limited use, so might not be the best test of durability but we’ll see. I did date each bulb on the base in sharpie.
It’s only for Android and it works alongside a USB device (color or spectral meter) plugged into an OTG cable. In my case the cheapest one, a ColorMunki Photo (now sold as: X-Rite i1Studio) I got off eBay second hand.
As far as I can tell the biggest difference in them is that they probably emit more light towards the base of the bulb so for certain fixtures designed for incandescent where you want the bulb to light up the entire fixture/shade they probably work better than the usual “front loaded” LED replacement bulbs.
Just a heads-up of another possible entry: our local LIDL had a bunch of different Livarnolux led bulbs manufactured by OWIM Gmbh advertised as Ra>=97 at 2700K for 6.99CHF (about 7$) for a pair. I bought 3 sets of 60W equivalent bulbs (810lm) model 312396_1904 (on owim.de website) with 9.5W consumption (not very good efficiency at 85lm/W). Unfortunately I don’t have any measuring equipment.
Some pics:
As you can see, it’s the usual plastic base with likely bad dissipation, but it does get quite hot during operation.
@fneuf, I just noticed your OP says (with french?) CRI_Grade is somehow related to the “à la energy efficiency norm”? that you linked. This is really confusing. CRI_Grade should not be explained with a comparison to energy efficiency. How about this:
“CRI_Grade” is an initiative to Grade lights based on their color rendering, but with extra significance given to the weakest areas of modern LED technology.