I'm applying to study law, and my girlfriend is applying to study medicine, so I thought I'd offer my opinion.
Law is studied at so many more institutions, so I'm only really going to count the top Law schools to give a fair comparison.
I'm predicted 4As, my girlfriend 5As - so very similar grades. She had a lot more work experience than I had as well.
I've come out with 4 offers from 5 so far, whereas she has got 1 from 4... The typical offers for my courses are higher than hers, either AAA or AAB compared to normally ABB, but it seems so difficult to get a medicine offer.
Don't know about the comparitive difficulty of doing the degrees, but I'd say medicine is a more difficult course to get on.