I took the 2 lights out for my nature walk tonight and my impression follows. These Convoy’s are bigger/longer than Emisar D4V2 but still fit in pocket pants easily. I have a preference for the small form of D4V2 but then D4V2 has only 18650 battery, and the larger thermal mass (Convoy being a larger light) of the Convoy dissipates heat better, leading to less step-downs. Both lights turned fairly warm but not too hot to hold. They are as expected very floody with low level throw. I installed the metal clip (see link in post #1above) to keep them from rolling off the table.
219b: Most of all, continues to impress with its ability to make shades of colors stand out. Light grey vs dark grey of barks, light green vs dark green of leaves. Every color, every shade stands out clearly. The rosemary plant for example: small blue flowers stand out against green leaves more clearly and beautifully.
519a: Clearly brighter than 219b. The warm yellow-golden tone is very soothing to my eyes. This is the light I would use if I am not trying to see the different shades of brown soil and grey barks .
Convoy hit a home run with these lights and I recommend both, without reservation. I believe they are the first 21700 lights with Nichia 219b/519a. Personally I wish they have on-board USB-C charging but then they wouldn’t cost 30 bucks. If you are new to this hobby or don’t have any Nichia light, these 2 and especially the 219b should be very nice addition to the collection, IMHO.
Pic of the metal switch and clip from Convoy (see discussion in post #1 above). For me the metal switch is a must-have for the 12-Groups Convoy UI as it makes both “click” (full press) and “tap” (half press) so much easier to engage. Especially the half press since there is a now a “built-in” FIRM stop at half press, the fixed outer metal ring. They are also VERY pretty.