I don't disagree that those are potential cons, but it also highlights how much versatility you can have with a fountain pen. For instance, there are ones that travel very well with shutoff valves to prevent ink leakage. There are options for filling that can all but eliminate getting ink on your hands. Nibs can be tuned and ink choices can align with what paper you write on, so you don't absolutely have to change the notebooks you use.
You highlighting the language issue is interesting because it makes the assumption that one can get the line width they'd like from a ballpoint pen, which personally, I didn't. Ultimately you need to choose what works best for you, and the language you write in is certainly a consideration. I'd much rather have the option, than be stuck with "one size fits all" of most ballpoints. So saying that's a con is a misnomer for me.
All that being said, a fountain pen is not a tool for every use case. I was a lot happier when I realized that a ballpoint or rollerball is far better suited for tossing in a bag or having at the ready when traveling.
The filling mechanism of the pen is what tends to dictate whether there is a shutoff valve, and there two mechanisms that have this feature; vacuum fillers, and Japanese eyedroppers.
Vacuum fillers are generally higher end pens, but the best, cheapest option is a PenBBS 456, which is a Chinese pen. The Pilot 823 is very well loved pen in the community, and a good "next level" pen if you're looking for one. Viscontis are high end luxury pens that feature a vacuum filling mechanism, although their marketing calls it a power filler.
Japanese eyedroppers aren't really a "filling mechanism", per say, but can be thought of in that manner, even though you have to fill them with a syringe or pipette. Unfortunately far fewer pens make use of this, and tend to be very high end pens. The one exception are pens from Opus88, which pretty much all feature this mechanism, and are very reasonably priced. Then there's a big gap until you get to the high end urushi pens like the Pilot Emperor.
There's other one offs, like the bulkfilling mechanism from Conid and used on the PenBBS 355. The Diplomat Nexus uses an integrated shutoff valve that's engaged when capping the pen.
You highlighting the language issue is interesting because it makes the assumption that one can get the line width they'd like from a ballpoint pen, which personally, I didn't. Ultimately you need to choose what works best for you, and the language you write in is certainly a consideration. I'd much rather have the option, than be stuck with "one size fits all" of most ballpoints. So saying that's a con is a misnomer for me.
All that being said, a fountain pen is not a tool for every use case. I was a lot happier when I realized that a ballpoint or rollerball is far better suited for tossing in a bag or having at the ready when traveling.