I LOVE vintage pens. They all have their own character. And it's like what other people have already said -- they can be fragile, but they can also be a lot more robust than modern pens. Remember -- they're often from the era where fountain pens were in everyday use, and weren't designed for "planned obsolescence". You bought the best pen you could afford, and used it daily.
Many modern acrylic pens kinda all look the same to me. Without looking at details, I couldn't tell a Rosetta from a Bexley from an Edison from a Noodler's acrylic Konrad. Most vintage pens, OTOH, are very individualistic -- I would have no trouble recognizing the differences between say, a Sheaffer Balance and a Parker Vacumatic and a Esterbrook J pen. And the pens are often a lot more attractive looking, with really beautiful celluloid colors. Even on the third and fourth tier junkers.
And they're often much better writers -- again, they're from an era where pens were tools, not collectors' items. The nibs are often better made and there's more variety of widths and flexibility. For instance, I now have four Sheaffer Snorkels -- an EF, a probable F, a probable medium, and what may be a BB that is *also* oblique! And that was the least expensive of the four! For many modern pens you're lucky if the nib range goes beyond F, M and (maybe) B. Esterbrooks in particular have a huge range of nibs, from the student grade 1xxx series to the "high end" 9xxx series. And while some of the more exotic nibs can be pricy, they can often be found -- and on a pen, no less -- for a whole lot less. I think, not counting repair costs, that the most I ever paid for an Esterbrook was about $35 US -- and that was on a black LJ with a 9284 (signature stub) nib last month at the Ohio Pen Show. Many, I've gotten on Ebay for under $15. The most I've paid in the wild was around $20 (although I have seen them for more, I won't pay the prices some places were asking, even for 9xxx nibs). I actually found an SJ with a 9128 (flexible EF) nib for $20 last summer.... That's less than I paid for for one on Ebay a couple of years before. (Okay, most of the pens I've gotten probably have F nibs, but I'm okay with that.... )
Even with repairs, those vintage pens are a lot less expensive, in many cases, than modern pens. The fill systems are really cool and interesting -- as opposed to modern pens where probably 85% of them are c/c fillers. I like that I'm not tossing spent cartridges in the trash any more. I like that I've rescued something from ending up in a landfill -- something that my parents might have grown up seeing (if not actually using, given that they were both Depression era kids, where one grandfather was a coal miner and the other was a not-always-employed musician).
Ruth Morrisson aka inkstainedruth
"It's very nice, but frankly, when I signed that list for a P-51, what I had in mind was a fountain pen."