I always have like a ton of them, they're handy, and since I don't live that far away from the UK, it takes like 3 days to recieve them (I shop online). And I've also tried out their nibs which are sooo super hard to learn how to draw with, but so far it's top notch quality for a rather cheap price! :D
I can also recommend, if there's a need for black ink pens, the Uni Pin Fine Line is awesome when working with markers. They don't bleed out (neither does kuretake, which is a WOOOHOOO thing, haha!) on the colours which is perfect ;D