I have two of these. One with EF nib, and one with F. More on the way.
EF is really extra fine, but the F is (sizes write on the nib) medium for me (the thickness is same as default x750 nib thickness) on my case. And the interesting part is that my EF nib is unhooded (which I like). I got the F one just for the sake of the nib (I was going to apply it to Baoer 388), but after seeing its thickness and nib smoothness I'm currently using the pen to test my ink mixes (I mixed a $1 Zycc (Cheap Chinese ink brand, popular on Aliexpress with 15ml bottles) blue-black with black to make a darker blue-black, I'll try with Diamine inks to try to make my Prussian Blue a bit darker).
Anyways, the problem for me with this pen is, for the both of my pens, the cap starts to crack from the plastic thingies (there are 5 plastic thingies inside of the cap to make it "click" and keep the body and cap together). And for both of my pens, the cracks start just over this plastic.
This clearly shows the plastic material is either too hard, or too tight so it makes a tension every time the pen caps and uncaps. I had to tape from outside of this cap from this support section to prevent the cap from falling, and sadly this looks ugly. Any suggestions would be appreciated.
As for the nibs, a little tine adjustment, both of these EF and F(!) nibs write like a baby. I didn't need to use a grinder or micro mesh etc. Definitely worths the price.
Apart from that, currently, it's $0.50 on Aliexpress branded as Jinhao 994 (limited to 1 purchase per account) or ~$0.81 as Jinhao 991. I guess the matte version of 991 is named as 994, but not sure and can't say much about it.
By the way, has anyone tried to eye-dropper this pen? There's a YouTube video but no instructions. Is silicone grease needed ? The transparent one would look super cool with eye-dropper conversion.