[iamwithnail]

Let's be realistic here. I'm in the same boat, I'm Scottish and British (identity) and have a British passport (citizenship), and live in London. It's very unlikely to be an either or, and I believe the contingency right now is that in worst case, British passports will be honoured till expiry. But likeliest is dual passports. And what of my son, though, while we're on this? He's English, born here to a Scottish dad and English mum. Will he get a choice (or us on his behalf)? That exercises me more than my own passport.

On your initial question, it'll just be a straight up question of what's more important - a passport that reflects your heritage but that might have more visa requirements for a few years, or retain your existing one. If it came to it, I'd take the rUK one for now, it's not a big issue - it's like all the people I know who're from other countries and also have a UK passport.