This may or may not be of interest, but I've been using a batch of these (Nitecore NL166) for a good while, and they're doing OK and tested well when new. My main interest was satisfying the current requirements of an Elzetta Alpha Gen 3 @ max output, while also being short enough for an ET D25C. They're very short protected cells rated @4A (presumed cont rating). They're only rated @650 mAh, but exceeded that when tested w/MC3000 @ 1A to 2.8V. The bad news is that they've been discontinued, having been replaced by NL169 rated @ 950 mAh, but at lower current rating:
flashlight.nitecore.com
The 'good news' is that they're apparently still available if you want to try them, as I see this place still lists them and doesn't state otherwise:
Shop everything 18650! Rechargeable Lithium-ion 18650 Batteries, Chargers, Wraps – for custom battery packs and more! Popular brands for 20700, 21700, and 26650 battery sizes available.
www.imrbatteries.com