Aspire has a bigger capacity , and also has a lower IR that allow lights like D4 (with direct drive) to draw more amps compared to the Efest (so it has a bit more lumens) .
The Aspire 1100mAh 18350s have much better current handling abilities, versus the Efest 700mAh IMRs, up to 10A, at least.
While the 18350s aren’t ideal for the D4, I got two extra Aspires just to have. I use them in a 3Tronics XP-L HI triple that Ven got me, which pulls about 6A at the tail.
I got my D4 yesterday and use the Aspires and the Sony VTC-5As.
While I like lipstick sized lights for EDC, I’m going to keep my D4 configured for the 18650 and deal with the weight penalty. The pocket clip I also got, doesn’t fit the 18350 body, so that’s part of it.
Chris
Thank you for the info giorgoskok
The 18350 configuration is cool, but I also like to edc the light with a samsung 30Q 18650. I also have the deep pocket clip that doesn’t go with this
light but works fine. It goes to some convoy lights that I assume are similar in size to the D4 .
I find the D1 works particularly well in 18350 form with an Aspire cell. I usually leave my D4 full-sized though, to work better with a clip and increase runtime.
By the way, thank you for your review.
I’ve looked it over many times, very useful info.
After a while using the “Convoy’s” pocket clip on the D4, today I received another one, similar to the one used on Astrolux MH10.
Fits nicely on the 18650 tube, but not on the 18350 (hinders the head from moving) 
Still, it is nice! I had to bend a little bit the tip to make it fit better!
That looks very similar to the official D4 clip. I’ve seen that design used a lot lately on several products from several brands. Not sure why, but it seems to be a thing lately. Lumintop wanted to use the same clip on the FW3A, but it was a bad fit and got vetoed.
Yes, indeed it seems! This one is black, though, and is not the MH10 “official” one!
I don’t know good it is but I broke one of them trying to bend them a little (on the middle)! :person_facepalming:
So the material is not very flexible! But it fits well on the D4.
I wish the material of these I own was more “bendable” to make it fit the smaller tubes! Still have to find a nice one for the 18350s…
Other brands are using this “design” in smaller size, like some Sofirn flashlights (SP10A/B and SF14), and a similar design in bigger lights (Sofirn SP32A) (examples from what I own, only)!
And I know this is off-topic, but I’m glad this will not be used on the FW3A! That light needs a “own” pocket clip 
Surprise,surprise, my D4 with 18350 body and clip came today. everything works with 18650 ,charging 18350 now. everything is good. very happy with light, I guess be patient.
Your light arrived without ever having received a tracking number/hearing anything from Neal?
James, thanks for the offer but mine is 219C I might have another go at ordering a grey one or maybe a grey D1 but not until I’ve saved up a few more spare beer tokens.
Quite like the cyan now, think it would look good with a heat treated titanium bezel maybe……
I would say it is the exact same clip except the colour.
I got a few of them from BG
They work pretty well on the D1 and the D4; Only at the D1S a pocket clip makes no sense because of the big head :person_facepalming:
The d1s works very well with a clip.
I can confirm the Emisar clip is the same as the M01 clip.
Only the M01 clip is black powder coated and the Emisar clip is bare stainless steel.
They also fit very well on Convoy C8 by the way.
Any more info on the D7? Seriously looking forward to it…
i think it will be very silent and secret and out of nowhere drop like a bomb like the d4 did… hope so its fun not knowing much and then baam there it is …
I received it today 01/12/18. Took just a bit more than 1 month. The light is beautiful! I got the Neutral White - XP-L HI V2 5D, 4000K and I love the tint! I love the user interface too. So easy to use unlike the BLF A6 and Astrolux S42 that I have. Additionally, it works beautifully with my panasonic protected 18650. I’m not sure why on the website it says, “Unprotected, high drain batteries only, protected cells won’t work”.
Still waiting on mine but its only been 13 days.
Waiting as well. Its been 32 days now. I’m sure I’ll see it this coming week. If not I’ll send Neal a Massage. All good 