the subjects done in biomed are just structured in a way so they are geared more towards medicine and are just integrated bio/chem subjects which are relevant to medicine (+ physics and maths that are apparently relevant when you will never use them in real medicine

). it's considered one of the better preps for medicine, however, in science you can do subjects which are very similiar if you do first year bio and chem subjects, then in second year choose mostly second year bio/chem (incl. anatomy, physiology, biochemistry, pharmacology - if possible) and then selective subjects towards your major (science and biomed share majors, but science has more), and do a major that you'd want to have done in biomed, then do 3rd year bio/chem subjects on the side. and voila! it's pretty much the same as biomed, there is not really a huge benefit at all by doing biomed over science (if the subjects are chosen right) they are both very good at preparing you for medicine/health sciences.
if i didn't get in biomed, i would be happy wth science and just choose similar subjects and so it's cool. (however i wouldn't do physics or maths in science as i have to do in biomed, and do psychology subjects instead... so science would be better personally) thats a better thing about science as you have more choice

so do science and be proud - do subjects you enjoy more then the structured biomed..
rambling..
You will get a better GPA in science, so just stick with that.
not necessarily, the subjects aren't harder in biomed, they are just different.