It will be the same, as it have temp. control, so both will be stucked on 55°C 
and btw, I dont thing that there will be any noticeable difference, as they are nearly 1:1 copy
depend wich arrive later at 55°C
That mean it have better heat management
but yes they are very similar,apart pill S21A that I like much,hope to see this pill in copper for single and triple/quad.
Spring bypass just ripped off from spring after 3months… On both sides
I guess its ’cos cable isolation become very stiff due to heat
At least it is easily repairable! The reverse threading of the switch end can be a bit of a pain though.
I wonder how the SST40 would perform with a straight FET+7135 driver in the S21A?
So far I’m adoring the Cree XPL2-HD with the MTN-20DDm in the S21A.
I use solder wick, massive current flow and worry free
I’ve seen solder wick broken so many times I won’t use it for a bypass, don’t even own any. I use Turnigy wires and always try to put a bit of a coil on them so they compress rather than bend. 
One more question:
How it is with waterproofness on this light? Can it survive dipping into water for few minutes?
It does have the required gaskets and if ya build it right, they should do the job of protecting itself from the occasional dip a puddle.
I like if Convoy would use quality double springs and button top on Driver instead of spring bypass to avoid wire desolder.
I don’t like button contacts on the driver. I consider it much better to have springs at both ends of the light.
That way you don’t get a momentary disconnect if you drop the light on its tail and the cell pulls away from the driver button as it bounces on the tail spring. Those momentary disconnects create an unwanted mode change on lights with reverse clicky tail switches and a half-press mode change UI. Really annoying if your light just went from moonlight to turbo or vice versa.
Springs at both ends also help to prevent “cell hammer”, which is what happens after a really nasty drop where the tail spring propels the cell back into the driver with such force that the driver PCB cracks and kills the driver.
Spring bypasses with multi-stranded flexible silicone-insulated wire are the value option, and double springs (as you said) are the gold standard.
I was asking because I needed to illuminate dark basement while working for few hours, so I was thinking about putting the flashlight into glass of watter to keep it cold, so it could run on turbo for infinite time
Could anybody tell me the diameter of the battery tube? I want to buy one shockli 21700 4550 22a/30a for the s21a that is coming but I think it will be too thick.
Thank you
I measured 21.48mm with my calipers. I use Samsung INR21700-48G which fit just fine.
Nice it has a true Constant Current FET driver, but a shame a 10% mode was sacrificed for a moon mode.
In fact, it seems all Convoy drivers have sacrificed a necessary mode for a moon mode, ruining the mode spacing.
Thank you Terry
Finally ordered 2 x LG21700 from Convoy.
Simon said that there will soon be a 17mm 5A constant current FET driver available with Biscotti.
Ah, now we're talking.
Finally got my first S21 from banggood this week. I don’t hate the 6500K as much as I thought I would, and I love this light. I EDC a Jaxman E2L, S2+, or BLF A6 in cargo pockets, and after a few days with the S21, it really doesn’t seem bigger for my carry purposes.
And the idea of a 5000mah 21700 with a full day of runtime makes me giggle as much as the throw of SBT90 in my new FT03S.
When there’s a version with a warmer tint and biscotti, I’m definitely getting another one of these. Ah, who am I kidding, I’ll probably buy more just like this when they go on sale again. Just an amazing deal for $17.
Sent out for an astrolux s42 lens from BG, and cleaned out Kiriba-ru’s spacers - can’t wait to quad this up!
Guess what… there are S21s with 5000K SST-40 and “12 mode group” (clone of Biscotti) UI: 13.68€ 29% OFF|Grau convoy S21A mit luminus sst40, kupfer DTP bord und ar beschichtete innen, Temperatur schutz, 21700 taschenlampe, taschenlampe licht|Taschenlampen| - AliExpress
You could probably also ask Simon to install and XP-L HI of your choice into the light as well. They match well with the driver, I swapped one into my S2+ with 5A/12 group driver and am enjoying it for a cheap beater light.