So I'm looking to get a couple Airport Expresses to be able to stream music to a few rooms in my house. I also would like to be able to use one for wifi when I travel. I don't need N speeds because it's just a backup in case a place doesn't have wifi. Is there any good reason to get the current or older N airport express, or should I just pick up a couple of the old G ones? Can get the G ones for about $30 less. But want to make sure they're compatible with Mountain Lion, iOS 6, and AirPlay. Thanks.