Let me rephrase the question a bit for you...if you recommend a camera system based upon a sensor, then i wouldn't want a hear a recommendation from you anyways.
And answer that by saying that since the 5DII, I haven't seen a Canon camera with a sensor that was significantly better enough for me to want to buy it or recommend it to anyone.
i would look at whether or not the system fits the person, support, service, used market in the area, what they want to shoot; and recommend based upon that.
a sensor? wont' be as relevant as the above would be in 2-4 years time.
In 2-4 years time, I expect people with Sony/Nikon cameras to be taking and editing photographs that Canon people simply can't - at least not with the same level of detail and color. I fully expect Sony/Nikon cameras to have 15, if not 16, bit ADCs in 4 years time. As for the system? They'll fill that in. The vast majority of users don't need more than a handful of lenses - thus "a system" that has macro, T/S, etc, is meaningless to the average photographer that will buy a camera plus lens kit and use that for the next n years without buying anything else. How many people is that? There's a thread on here somewhere... the number of people that buy extra lenses is less than 10%. i.e the "system" is meaningless to 90%+ of the people that buy Canon cameras.