I also just bought an AFE filter and installed it. I thought the install was going to be worse than it was, but ambient temps were in the high 60s, so that may be why. It fit the airbox fine and seems like a well-designed unit. I didn't really notice any meaningful change in sound - maybe a little more high end whine/whistle under load, but it's so faint it may just be my imagination. Any change in power would be hard to detect, but it may have pulled a little better on hills in a higher gear or it may be that I didn't have a passenger like usual when testing it. I haven't had it long enough to see what kind of MPG difference it will make, but I will be watching.
I haven't used AFE before so I don't know about dust issues, etc., but I may change my oil more frequently than 10K miles (which seemed a bit long anyway) - maybe every 5K to 7.5K. My '07 Civic which computed the engine oil change interval based on usage, usually went to 7.5K, so I don't think I'd want to go any longer.
That's my .02...