I loved my Birdy. Never disliked it. But once I got the Brompton, it started gathering dust. With a Swift and a Moulton next to the Brompton to handle all sorts of riding, the Birdy was completely redundant.
However that doesn't help you...
Maybe if I didn't have the Moulton, I would still have the Birdy. No mistake, that is one heck of a nice folder. It was may main commuter for a long time, didn't keep count but perhaps 2 years? So I put in a major stint on it and it wasn't because I was tired of it that I sold it. Perhaps they are too close to each other... I am not in need of wide gearing so that doesn't swing it for me. I toured on the Birdy and the wider gearing was good but I have similar options ready to go on the Brommie.
So, not clear... maybe it is simply an issue of want.
Very much an issue of want
The Brompton is the ultimate multi-modal urban commuter while the full-sus Giant MTB is built to handle everything else. I like to think the Birdy would be my jack-of-all-trades - small+light+fast+flexible and certainly sharp-looking in a manner the Brompton isn't. And I can't help but feel when I go down curbs and over rough roads that the Brompton is protesting.
I love my B but the n+1 itch is magnifying all the minor flaws.
Did you use the Expedition Rack when you toured? I was even considering the Birdy Tourer but the ugly color (IMO) and extra weight seems like a poor compromise when the chance of me touring with it is probably quite low.