Personally, I took the PCAT once in July, and I felt it was fine. You either study a lot during your winter break, or you study a lot during the summer...I recommend the summer cause you'll get more time, and winter break was my 'break' for the next semester. And wtf studies on Christmas and the holidays?
The PCAT was not very A&P intensive. Rather, it was passage based and you have to focus on what parts of the passages are important in the question. They give you more info than you need to waste your time. I got a 96 on both my science sections, but a 75 in math (didn't finish, randomly clicked through) and a 60 in reading (lol never good at RC, anyways). I studied for about a month during the summer after a summer class. Very doable.
GOOD LUCK!!