Seems like most are passing on this light on account of the PWM issue, but when I went to check my tracking number today I noticed some new stuff on the site. In addition to the Cree and Nichia, this light now lists the following emitter options that AFAIK weren’t there before:
SST20 4000K FA3 CRI95 (+$1.00)
SST20 2700K JA3 CRI95 (+$1.00)
Got mine today, didn’t have any previously but it seems like a decent light.
I spent far too much time figuring out the tail switch, pretty clever design. I couldn’t easily budge the pill on the head side though. I’m guessing I can use the holes the LED wires go through to leverage the pill out?
The pill looks a bit like a (recessed) washer with threads for the head protruding on one side and threads for the body protruding on the other side. I guess you removed the head-part. It’s a bit of roulette which part come off first, head or body. If things go as planned, it should be the body part. Just as seen in the thirf picture of the OP. So I use a tiny drop of glue on the head end of the pill, in the hope the other part comes off first.
The pill is not (eg. should not be) screwed in with a lot of force, it is the side you put a new battery in. So it should come loose by using a rubber strap. Or by using rubber (garden) gloves.
Guess what appeared this morning in my door?
Yes!! The SS light 
My perspective: it is small (not the smaller AA, though, if compared to the DQG Slim Ti), it is heavy (heavier that other AA lights and even some 16340s, but…it is Stainless Steel), it is very well done (no apparent flaws on machining anywhere), it is robust (really robust, what makes it ideal for EDC), the beam is pretty nice ( mine has a vey good Neutral White, I chose the Nichia 219B SW45k D220 R9080 4500K). The UI is straight forward, 3 modes without memory, no complains, and I just didn’t check for the PWM or driver whining. Like 
Also, flat top cells such as the Sanyo UR14500P may not do contact with the driver because of the retaining ring! Button top cells work.
About chemistry, I tried the Lumintop 14500 Li-Ion cell and it lit up and immediately shut down again. I thought I had fried the driver, but then I tried an AA alkaline and had no problems. So, using Li-Ion cells may bring some issues!
I am really happy that Fireflies did these lights again! 
Some work with 14500 and some don’t. Luck of the draw I guess. I asked by email and was told they can use 14500. This was over a year ago. Mine does.
Yeah, seems there are very different experiences with this light! I guess mine will only take a 14500 when I mod the driver (hopefully)
It’s a strange light, but very likeable. Glad you like it.
Maybe one day we find the perfect “blf” driver for this light.
I got excited when I saw the 2700K option but then I saw the comments about PWM.
Why go to the trouble of getting a warm, pretty, high CRI emitter if it’s going to be rendered ugly with headache-inducing PWM?!?
Referencing your pic, what are the lights? I think that’s a Tool Ti on the right side.
Yup, you are correct, the one on the right side is a Lumintop Tool TI (AAA/10440, modded by CRX)!
The line is (left to right):
1- Nitefox ES10K (Stainless Steel, AA/14500)
2- hc-lights SS AAA (Stainless Steel, AAA/10440, similar to the BLF 348)
3- Amutorch S3 (Stainless Steel, AA/14500)
4- FireFlies SS AA
5- DQG AA Slim Ti (Titanium alloy, AA/14500)
6- Lumintop Tool Ti (Titanium, AAA/10440, modded by CRX)
Mascaratum, you forgot to mention that it’s the AAA version of the Lumintop Tool Ti
I did not my friend 
It is on the confirmation of nightwalker’s question
But I’ll add the info on the list 
Just wanted to report that my Enogear AA Stainless Steel just went dead one day (been like it since February 2020). It was mainly a shelf queen with very little to no usage and a Eneloop 2000 mAh. Turned it on and no light… checked battery with charger and battery was at 1.33 volts. Tried loosening and re-tightening tailswitch but no avail… if it did come on, it was intermittent and did not cycle between levels… nice looking “poor man’s” Haiku but sucks in reliability department. And no, I have not inserted 14500 into at all… I’ll have to place a tag with “All Show, No Go” on the clip.
Thanks for reporting that.
I have some issues with my latest one as well, only inserted a new Duracell alkaleak.
It sometimes works as intended, but sometimes it just steps down to a (lower than low) level and i cannot increase the brightness again.
Sometimes loosening and tightening the head works, but the last time (when i needed it) it didn’t and it stayed dim.
Did you try tightening the retaining ring or maybe unscrew body tube completely and use wire to rule out tail problem?
Not yet, i was hoping that when i buy a light, it works (is that too much asked)?
Will give it a try.
I ended up putting a FET driver in mine and SST-20 3500K but I am second guessing this decision since SS and tiny pill is not ideal for this. I turned the 219B in it originally blue instantly.
~400lm
In case it helps anyone here is the driver they are using as of this latest batch:
I tightened the retaining ring on the driver, unfortunately it made no difference.
I tightened the retaining ring on the switch assembly, which did make a difference, it seems to be working fine now!
I noticed that when completely disassembling mine to see how it worked. To fully tighten the tail retainer it ends up being just below the 2 cutouts for the lanyard and it’s not simple to fully tighten cause I think there is an O ring there for good measure.