Mostly a safety concern. I don't trust Airbus' preference for hard-computer controls of a jet versus Boeings soft-computer controls. I am pretty sure Airbus has a worse safety record than Boeing. However, I don't have the facts to back it up and I could wrong. Overall both planes are safe and like I said, I'll ride in an Airbus because it is a generally safe product (compared to say a Russian made prop). I just feel more comfortable in a Boeing, especially when it comes to flying a new model. I'd rather let other passengers work the kinks out, so-to-speak.

Also I like the Boeing 777 over the Airbus equivalent. I find the Boeing 777 to be a more comfortable ride....less bumpy. I even prefer the 777 over the 747. I do try to look for specific planes when I fly (internationally), but that's only part of the decision.

And I'm sure some homeland pride factors in as well.