I agree. I can't think of many instances where an Advocate would be better than a Boulevard -- someone had mentioned that maybe in an older car without good side airbags there might be a slight advantage to the Advocate, but even then it seems the advantage may be negligible. Either way, I wouldn't want to travel with a Clicktight. Even the Britax rep I spoke with didn't recommend it for travel. It's super heavy and doesn't have any of the travel-friendly traits (folding, or the ability to attach carry straps) that make some other heavy seats possible travel companions despite their heft.
Do travel with a carseat, of course. Like everyone else suggested, you can pick up a Scenera for the money you'd save in getting a Boulevard over an Advocate. Or, if you really don't want a separate seat for travel (I'd understand!
) then you could consider the regular Boulevard, which is considerably lighter than the Clicktight and also a very nice seat. But it doesn't RF as long as the Clicktight and also expires sooner.
Also, while the Advocate should fit on an aircraft seat, it will be tough to carry on to the aircraft as it is wider than most aircraft aisles, so you'd have to lift it pretty high, and if it's installed FF you won't have much shoulder room if you're sitting next to it.