Hasselblad at all is better. Anyone who has held both cameras in hand, knows what I say. Hasselblad is the best-designed mediumformat camera which produced so far. Phase One body is very poor ergonomics, poorly balanced, the grip is too short (sticks in hand), by fitting the V-grip can work, but unfortunately it is not well designed, bad choice of wheels are arranged, after an hour of work is being felt pain. All the time you have to use two batteries, one for the body, one for DB. Also circulated a myth that the Phase One camera is smaller, lighter and has better optics. I strongly invite you to test, I use both systems and I know what I say. In the case of the Hasselblad can talk about your system, in the case of Phase One did not. Still a lot of work on the Phase One camera system.
Sorry that I focused on the camera, but the many myths that must be overturned.
Returning to the differences between the P40 + and H4D40. AF System: Hasselblad has a much faster and more accurate autofocus (White LED), the system works perfectly True Focus (3-point autofocus system Phase One looks at it as an archaism.) Hasselblad has a range of 11 lenses
But the most important argument is the image quality. H4D40 is according to me the best camera, which was developed over the last few years. Color reproduction is excellent, the quality of images above 200ISO is unbeatable for Phase One. You could say that it is an entirely different league. Of course, "Sensor Plus" gives better results, but 10Mpix this is not what is expected for the hardware for the money. I strongly urge everyone to test and compare.