It's horses for courses, really.
What will you be doing with the footage? Just storing it and viewing? Or editing? A little trim here and there with iMovie? Or working on a magnum opus as your calling card for Hollywood?
If you're thinking of something to grab the kid's party, stick a title on it and send to grandma, then 264/mp4 is perfectly good. If you're into something more serious then consider AVCHD. But AVCHD is difficult to work with, requiring transcoding and therefore large file sizes.
So, depends on what you want to do...