Yeah, it's a bit of a bother logistically because of where the embassy is located, and one cannot be sure you get processed that day if the queues are long. So I keep just one of the passports as paper version (the country where I reside) and use that when travelling. For the other one, I have no paper passport; I do have the social security number which I can use when necessary.

Mind you these are two Nordic countries so it is not much of a difference either way.

Even for voting, which the tool misses, is conviently done. I vote in country B elections from country A. They have lists of country B social security number with a name for the eligible votets, I have the paper which they mailed to me from B and present that while I prove myself using passport/driver's license of country A. Then I vote remotely, in advance to the actual voting day.

Voting in EU elections works the same way, but is done for one country only.

Hmmm. I have dual citizenship for Australia and Estonia, both of which offer 10-year passports. It's also possible to moderately easily get the 'other' passport when located in each country. Thinking about it I guess I could be pretty fortunate, and this might not be the case with other combinations.

For what two countries are you a dual citizen? Which one isn't worth the effort to keep up to date?

I'm a dual citizen for the United States and Mexico, and it's fairly easy to update my Mexican passport here in the United States - not sure if that's the case inversely.

For many you either need to do it in the issuing country or at an embassy. Example: https://ottawa.mfa.gov.hu/eng/page/utlevel-igenylese

I live in vancouver so my choices include a 4.5 hrs flight to Toronto, paying very close attention when they travel to Vancouver (which is effin rare, see https://ottawa.mfa.gov.hu/eng/page/kihelyezett-uegyfelfogada... -- right now if you try to get an appointment you simply get a 'no appointments available' error) or just renew my passport in Hungary. For me, that's relatively easy since I am back there at least twice a year so that's OK. But the bastards just changed the procedures so the valid date is your last birthday so when I recently renewed I got 9 years and 1.5 months instead of ten years. And, if all goes by plan in a few years I won't travel to Hungary ever again so this will become a major hassle but as long as the idiot government doesn't pull a Huxit it's still worth it because it gives me free movement in the EU.

For my European country, you can renew at the consulate in San Francisco 1-2 times a year, but the slots sell out as fast as Burning Man. The passport costs ~$200, and I think it's only valid for 5 years, not 10, when you're not a resident.

I have been hit with $150-200 visa fees 2-3 times with my US passport that my European one would have avoided, but in hindsight it was a good deal.