Any pen model can have the occasional lemon.
I've heard a lot of praise for the Himalaya and I have not had any problems with them myself (other than the aforementioned dodgy stub nib).
I haven't really been aware of the leaky cap issue on the FPR Himalaya until the last 24 hours, because even though I "should" expressly test caps for airtightness — or specifically against leaking where the clip and/or finial joins the main body of the cap — I generally don't, especially if there is a screw or spring in the roof of the cap.
However, now that I'm aware, and it seems there is no metal part at the roof of the cap, I decided to put the caps of all six FPR Himalaya v1 pens in this household to the test, standing them side by side atop a paper towel in a test tube rack, then putting a single drop of ink in each cap (alternating between Diamine Evergreen and Diamine Red Dragon) and then filling them up with water.
Wanna take a wild guess how many exhibited leakage after 10 minutes or so
by way of colour of the paper towel under them?
The answer is five out of six. What was most surprising, was that the leaky Emerald Green acrylic cap was the slowest to leak this time, such that there is no green splotch beneath it; it took touching a tissue against the rim of the metal clip to detect any leakage.
As for ink leakage from the converter into the barrel, I don't know how to speedily test for that. However, I must say I've long thought the the converter in the FPR Himalaya — including the smell of the material of the hollow tube, and how it screws onto the section but with the converter as the "female" side of the join — is the worst part of that pen model, even though I still don't expect every converter for the Himalaya to leak with every fill.
Also I've found FPR's customer service to be pretty good, so if you do order one and have a problem I expect they'll take care of you.
I'm sure Kevin would send me a replacement converter if I tested and confirmed that one of the converters is always leaking ink into the barrel, and reported the issue to him, irrespective of how long I've had the pen.
On the other hand, I don't think there is much he can do to fix the leaky caps, which seems to be a pervasive problem. Of course no user, including myself, is going to routinely fill the cap with water, but the fact is that there is evidently an avenue for air to escape from and into the cap, thus causing more evaporation of ink to be possible than if the cap was airtight.