Fair enough - my opinion is based on the fact that the Canon PTP support on Windows is inconvenient to use, a major resource hog, and accomplishes nothing significant that USB mass storage protocol couldn't do. That's partly the fault of the Canon software for not implementing some of the more advanced control functions. But regardless, the most important and useful feature of the interface is to be compatible with the widest variety of host devices possible, and that's where PTP fails miserably.