So, to follow up my previous post, as I see more people experiencing dry nibs on the 991:
I had a pretty extreme case in one of my two 991s, but I managed to address it completely and now it writes very well. All I did is hold the pen against paper @ the angle I write (or a bit lower) and push down to force the tines open. The nib metal is rather malleable and easy to bend, as I found out later, while experimenting, so go slow, and repeat 4-5 times until it flows as wet as you like.
Having corrected this problem, I slowly fell in love with the pen. I have the completely transparent demonstrator version, that I prefer because I can use with any color ink I like (I am a bit anal about matching pen and ink color). I like the minimalist aesthetic, the light weight but relatively sturdy construction and the section width that feels just right in my hands. I like that the cap seals well enough to prevent the nib drying for up to a month with most inks (I had some premature drying with Pelikan 4001 inks). I also like the feed (wet but not gushing) and the smooth nib that produces more shading than all of my other fine nib pens. I also like that it is very easy to remove the nib for cleaning or changing. I found out that the nib (and the feed) of the Hero 5028 fit perfectly in the Jinhao 991, so I now have the 1.1 Hero nib in one of my 991s, as I much prefer this pen's body to the 5028; paired with Noodler's Apache Sunset, it is my favorite cheap pen to show off.
I eventually bought 3 more identical 991s and didn't have a problem with any of them. So 1 bad - but correctable - nib out of 5 is pretty good for a pen that costs 1€ delivered! I am now thinking of buying 5 more; I am even thinking of buying an extra Hero 5028 set just for the italic nibs to use in 991s.
Thanks for the update about your experiences with these pens. 1 bad out of 5 seems to be a somewhat standard ratio for the quality control with Chinese pens. I also have a Hero 5028 1.1 stub nib in my 991. I tried using the 1.9 stub but there wasn't enough ink flow. I can also confirm that the seal on the cap is decent. I've only had hard starts with those finicky Noodler's inks that like to dry on the nib anyway. The ability to completely disassemble and scrub the feed assembly is a huge plus for those kinds of inks.
The 991 is my current top pick as a pen to give someone who wants to know what it is like to write with a fountain pen. I think I would pretest any such gifts, though, to eliminate duds.
I agree, I would choose a 991 over a Pilot Varsity of Platinum Preppy any day as a pen to casually introduce someone to the FP world. If it was for a gift though, I think one of Jinhao's metal options like the 165 or 500 would be more classy. The 500 I got last week has become one of my all-time favorite pens.
We may be getting off topic, but my Pilot V-pens and Petit1s are way better at starting up after prolonged idleness. I have found them to stay ready to write after more than a year idle. It is probably due to a combination of a well sealing, stepped, inner cap and the wick feed.
It's definitely the wick feed that keeps those pens from drying out. They are one step ahead of Platinum's slip-n-seal cap mechanism in that regard. I cleaned my Petit out many, many months ago and today there are still water droplets in the cap! However, the downside is that it's tricky to change inks with a wick feed, especially if you had some permanent ink in it previously.