Tom, I gotta say that I use iTunes with an Airport Express (selected for both the AirPlay feature and an optical output). My good ol' Onkyo 706 unfortunately doesn't feature AirPlay like many of the current receivers do.
That along with the free "Remote" app for iPad is a fabulous combination. Full access to the entire iTunes library, practically any way imaginable.
A well organized iTunes library is a beautiful thing.
I suspect that Ken will agree.
That said, I've not used other streaming solutions, so I don't have a real basis for comparison.
As well, it bothers me to no end that Apple continue to elect to not support FLAC directly, so I end up jumping through some hoops to get my FLAC songs (which I keep) into a format that iTunes will import. Still, it's not difficult, just a bit of a PITA.