To those taking the PCATs, does it really which is a better month to take the PCATS? I really think this is a somewhat silly question...I mean, back in high school, did you guys worry about when to take the SAT (Is and IIs) since the scores from the SATs, like the PCATs, are also affected by how others perform (though it's not quite heavily dependent on it as are the PCATs)? Since your score is affected by how well others do and there's probably an equal # of smart and not so smart people taking the Oct/Nov/Jan one, there's really no way to tell. You should just focus on you and yourself as opposed to figuring out the trend. If everybody knew about this trend, then, more "smart" people would take the PCATS at that particular time, thereby ruining the trend of "which one [of the 3 test dates] applicants do better as a whole."
No offense, just my opinion. I think you should channel your energy to doing more productive things, like studying for the PCATs so you can score the highest you can as opposed to figuring out a trend, even though some people may claim that "most people" they knew did better on a particular test date (I'd rather not get into all the details of statistical sampling...) 🙂
Best of luck!