What does that friend want to use the tablet for? Anandtech found the screen on the Surface to be superior for watching video, despite its lower resolution. Does the friend want to share his tablet with other people in his household? The multi-user support in Windows RT is obviously superior to the complete lack of such functionality in iOS. Does the friend need to occasionally edit Office documents?

I don't think there's an obvious answer to which tablet provides more value - it's very context-specific.