Mine finally came last night. My first impressions are that I like it, but I like the PenBBS 308 more. The nib I have in the M100 is smoother than the average nib I have on PenBBS pens, but not as smooth as the smoothest. I suspect the nibs may be more consistent. I like the Schmidt converter (would have preferred a K5) and that it takes standard international cartridges. And while it's as pretty as PenBBS pens, the darker colours make it feel more professional. So it has some clear advantages.
The no.5 nib looks silly, makes the pen a centimetre shorter than the 308, makes the section significantly slimmer, leading to a noticeable and annoying step-down (and I never notice step-downs), and the metal cartridge collar means it can't be eyedroppered. Also, there are some marks near the clip insert that make me nervous to actually use the clip. The nib is also very noisy, like writing with a pencil. Nobody else has mentioned it, so it may just be mine. I'll spend some time trying to get it wetter later. Somebody else mentioned that the cap cross-threads easily, which I can corroborate.
As I said, I like it, but I won't be getting a second. If they'd made the decision to go with a no.6 nib (which would have meant a wider section), and gone with machining the cartridge collar into the acrylic, it'd be another story entirely.
I got mine before Xmas on Aliexpress.
Aliexpress sellers are offering the Moonman M100 at prices ranging between $41 and $45 (but one even up to $58...)
Etsy sells it at $36.69
I bough mine as "KICUTE M100 / PENBBS Business Fountain Pen Acrylic Iridium Fine Nib Gift Box" and got the same pen in the Moonman box with the Schmidt nib, for $25 from HONG KONG YI HUI LIMITED.
Here is a seller currently selling at same price
My purchase details mentions that what I bought is
KICUTE M100 / PENBBS Acrylic Fountain Pen Iridium Fine Nib Converter Pens Luxury Gift Chic Wedding Signing Pen With Box
The pen looks very nice, that's not to be understated (the Acrylic is imported according to the shop), my version is blue/red/orange (Art Red, according to Etsy), I was really attracted by this finish.
I appreciate the big advances in Chinese pen making, however, the issues mentioned by JollyCinic are all there, plus others.
The worst is cross-threading, very bad on mine and very annoying, it takes me two to three attempts to close it every time...
The pen is smallish, 14.3 cm capped, 12.2 cm uncapped, which is not too bad, usable, interesting as a carry pen, but the section is slightly too narrow to be very comfortable. The step down is not so pronounced but rather annoying too.
I appreciate the metal threading which holds the converter and the barrel screws on, this is the biggest advance I can see on a Chinese pen, at last the threading is proper and not gritty. Pity for the faulty threading on the cap.
I don't really mind too much the #5 nib, if only it would write well. It's smooth enough, but starved on the right to left stroke...which is really unusual.
I will have to take a look at it more closely.
Presumably any #5 Schmidt (and probably also Jowo or Bock) will fit, and could be the solution If I can't fix the current nib.
I was curious to try this pen so I don't mind too much the $25 spent, but I would be much happier if it did not have this bad cross-threading issue, as this cannot be cured.