
Joolz
Aer+
Travel-friendly, city-nimble, but tiny storage and struggles off-pavement.

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I'd get Donkey but leave in US. Too bulky for cabs with luggage, could get damaged in checking. So you are getting them seats on the plane? I'd prefer Doona X because the Urbn flex is bigger and you'll need 2 and they can recline more, and people in dense cities usually prefer taking a Doona out in a taxi than the stroller system (and definitely not 2 pipas and a donkey frame) but either seems fine. In the US they'll usually do a car seat test if a baby is super small (like maybe under 6 lbs). Planning to baby wear (not in car but in transit) might be helpful.
If the first baby is coming back with you and also for the long term, I wouldn't do a mix of the Doona and infant seat (also you don't need to worry too much about the baseless status—the pipas with a base can all be baseless too). I'd go two car seats or two Doonas. Tested over 6' and found the Doona fine (it was the current one and not the X). A lot of people do complain about that but sometimes tall people also have longer arms! But here's a stroller influencer today advocating Nuna flex over Doona, a different answer to your exact question: [https://www.instagram.com/reels/DUDm363kQZS/](https://www.instagram.com/reels/DUDm363kQZS/)
I had the DoonaX and baby carried, then switched to the JoolzAer2 when he outgrew it. But - we live in a dense city and don’t have a car. So I just wanted to be as minimalist, flexible and light as possible. If I had a car lifestyle I’d probably want something bigger with more storage and would have gone with like a middle-size nuna. I’m contemplating a wagon for when my second is born because those double strollers look like they’ll be a massive pain on narrow sidewalks.
I HATE the doona. That thing is so stinking heavy and you can’t even have the wheels down at all times. They also outgrow it way too fast to justify the price. I also dislike some of the Nuna seats too which is a hot take for sure. As a shorty the umbrella ones are good heights for me but they suck to use. Why do they get stuck on a singular leaf?
We have one and primarily used it for travel as it was easier to have just one thing instead of 2. Also it installs without a base which is convenient when we were traveling with rental cars (but more options out these days for that, esp the nunas).
i love my Doona, for my babies first year i had to commute to work with him so it was a real lifesaver. i also used it when i traveled cross country to visit family. i still use it for short trips and if he needs to nap! ours was free from a friend and i cried when my husband brought it home
You have to take a typical travel system apart and put the stroller base in the trunk. With the Doona there's no need to do that.

Joolz
Aer+
Travel-friendly, city-nimble, but tiny storage and struggles off-pavement.

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