(As you asked me on the other thread...) I've no experience of leather. I'm sure they are lovely, will get more comfortable with use and they look great. You'll need a decent stapler to fit it. I've recovered a couple of seats in vinyl and it's really satisfying.
Unfortunately my bike lives on the street in central London, so intentionally I don't want my bike to look too good or of any value as it will get stolen. I'm only refurbishing my seat because I tour quite a bit and it's particularly uncomfortable.
Brett