@macattack510:
the two majors as a whole are pretty different, with one being VERY bio-based and the other being VERY chem-based. the upper-division biochemistry sequence for each are identical in requirements (one quarter each in structural, metabolic, molecular biochem) but taught slightly differently between the departments. The biggest change between the departments is probably that the chemistry department sticks like glue to the textbook offerings, while [I feel] the biology departments get a little more creative, often pulling in additional resources, having slightly more "thinking-based" test questions, etc. In the end it's a question of whether you like bio or chem more. I was surprised I ended up choosing chem (because I hated it to no end in high school), but I liked it a lot more -- classes were smaller, I could actually count on seeing my classmates every quarter, the professors were in a smaller department (and could advise with more experience), and I liked the mixup of subjects. Bio is pretty much a "sit and memorize" type of science for me, and I really didn't want to do that for four years.
If GPA is your concern, chem doesn't have as many grade-obsessed pre-meds. You'll see from my earlier posting that there are a number of us who are there because we like it, and could care less about grades.

But you're the one to ultimately decide if you're a chem person.
P-chem really isn't all that bad. Starting in fall 2005, they made a change in textbooks for the chem/biochem kids (who take chem 126/127, whereas the regular chem majors take chem 131/132/133, a notoriously hard sequence) and it's been watered down SO much compared to the old series. It's also being taught by John Crowell now, and he's excellent at picking out the necessary topics, ignoring the random extraneous ones, and organizing them in a very student-friendly fashion. His talent for that has also kept him teaching gchem for a few decades now.
@Dk-blue_Falcon:
aw man, you're making me go look up stuff now? :P I kid, it's an easy one enough. For many people, their GRE scores are pretty close to their SAT scores (since the two exams are, like, the same thing?), and mine was no exception. 1410 for general GRE, a 5.5/6.0 in analytical writing, and a 750 in the chemistry subject GRE.