I have leather in two vehicles. The original owner (of both of them) go the leather because she has dogs, and the dog hair won't stick to them.
I personally find them very easy to clean. All of our cars with cloth seats are filthy. The leather seats are very clean, and I do nothing to them. The floor of one van is terribly stained, but the seats... still clean.
However, I do stick to them in the summer. I do not like that feature. Once the car cools down, that is fixed. However, on minivan's AC stopped working, so I just try not to wear shorts when driving it.
I think if I picked, I would go with leather though, because of that clean factor. My boys are not the neatest creatures out there.