We had a Graco Quattro Tour™ Duo Stroller but it went back after our first airplane trip.

The BRU stroller tech swore that it woud work just fine and fold down to fit through the x-ray machine. Ha! Not only did it not fit but it got jammed! The TSOs were not happy about having to wrest the damned thing back out and then having to swab it. BUT! Once airside and everywhere else it worked great! It's tandem style (one kid behind the other) and so didn't take up a lot of space going down the concourse. It folds down reasonably well for gate checking, just not for many x-ray scanners.

When we eventually switch to a ::shudder:: minivan, we'll probably get another one but just won't take it for air travel. We've been looking at the Maclarens too but we'll wait until after the move.