For all practical reasons I agree with everyone else - it doesn't matter. There is a very slight performance edge using objects, since they don't require the extra memory allocation that an array uses, but objects are much less flexible. And optimizing this at the point of your development that any of use probably in? A waste of time.
Me - I have a tendency to use objects when I can, simply because I prefer the syntax. The more I work with complex applications, though, the more I standardize on arrays since there are so many useful functions in PHP for arrays.
