Your example:
If the choice was purely between 25% lumens versus 29% CRI and everything else was equal I’d probably go for the high CRI.
However, most low-CRI neutral white emitters tend to be in the 80 CRI range (at least for the ones in my lights). So going from low to high CRI usually means a gain of just 10-12 CRI, not the 29 in your hypthetical.
If the very large gap between low and high CRI in your hypothetical is because you were describing cool-white color temperature lights, then I wouldn’t have been in the market for either light since one of my criteria is usually “must be neutral white”. I find cool white to be harsh and unpleasant regardless of CRI and avoid them.
A more realistic scenario I face is like that for the Emisar D4 choosing between high-CRI nichias, or lower CRI XPL HI:
3800 lumens for the Nichia 219C v. 4300 lumens for XPL HI. And the XPL HI version has better tint, better color temperature, much better throw, and runs cooler so can maintain high output longer.
So yes, in your example I would probably go for the high-CRI option assuming both options were neutral white and did not have greenish tint. But the example you described seems unrealistic and exaggerated to me. When presented with realistic choices when buying a flashlight, the benefits of the high-CRI option (if there even is one) almost always seem to be outweighed by the tradeoffs.
I do make the decision on a case-by-case basis though, and do consider high-CRI if it is an option.
For example:
The light I received yesterday is high-CRI and I’m quite pleased with it. Zebralight H604C headlamp with high-CRI CREE XHP 50.2. This light features:
- 4000K color temp
- Tint is yellow, but not green. Quite pleasant.
- Fairly good output of 1700 Lumens.
- Small and lightweight
Overall, I quite like this emitter. It’s better than the 4500K neutral white XHP 50.2 in my Zebralight SC600w IV Plus, which has a slightly greenish tint. If Blizzard offered an SC600c IV Plus with the same emitter as the H604c, I would prefer it over the SC600w IV Plus. The slight reduction in total lumens would be outweighed by the nicer tint and CRI.