We stayed at All Star Sports in July when the parks were absolutley packed, and we found the bus transportation to be MUCH better and easier than we had expected. We took the bus 20 times during our stay and not once did we wait longer than 20 minutes (usually it was more like 5 or 10). The buses were generally fairly full, though, and the DTD route was very uncomfortably (almost dangerously, IMO) packed both times we rode.
I will say that we avoided EMH during our July trip; doing EMH might have made a difference in our opinion of the bus service--we saw hugely long lines early each morning for that day's EMH park, and we were always glad we weren't waiting in those lines!