That's the only fitting description I can think of. Advent Children is basically a 100 minute FMV. You get treated with breathtaking graphics, and that's about all you get.
Story and characters are about as shallow as it gets.
Story is better forgotten, and characters are actually impossible to remember.
Don't listen to the pants-creaming Final Fantasy fanboys out there, past the visuals there's nothing even remotely interesting to be found in there.
Watch it if you wanna take a ride. If you're looking for some substantial story or solid characters .... pass your way, you dialed the wrong number.