A genuinely important long-game decision, and one to make with proper information rather than forum instinct. Whether dual citizenship is allowed, the tax consequences of each status, absence limits on PR, and any obligations that come with citizenship all vary by country-pair and change over time. The Citizenship and Visa sections of your destination guide are the place to check the current specifics, and for something this consequential a qualified immigration lawyer (and, on the tax side, a cross-border accountant) is well worth it. Please don't base an irreversible choice on any single anecdote here, mine included.
I'm a few years off qualifying for either and genuinely torn — permanent residency keeps my original passport simple, but citizenship offers security that residency status can always be changed on you. There's tax, dual-nationality rules, and family to weigh. How are you all thinking about the PR-vs-citizenship decision for the long haul?