Domestically, we travel with our Zoe XL2 Best Double stroller (gate check) and 2 carseats (use onboard). It works well for us.

We recently took 2 umbrella strollers on an international trip. The biggest difference I found is the need for 4 hands (vs 1-2 hands) to push through the terminal....which left 2 fewer hands for our carry-on bag.

We have a Vista. But, we haven't taken it traveling in a long time due to its bulk and weight (I think it is too heavy to gate check on AA). Do you have the board that the older one could ride on?

Also, when our kids were under-18 mos, we really preferred baby-wearing in the terminal.