I personally liked AP, purely for the fact that it tended to cover more games than the other mags (and I bought most of the different Amiga mags that were available at the time). That does not mean I agree with their reviews (like for example, their constant preaching that Rainbow Islands was the best Amiga game ever produced). Of course the reviews are going to be biased - it is impossible to write an unbiased review as it is always going to reflect the review's tastes, however I might point out that AP was probably the only Amiga mag that regularly published other reviewer's opinions of the game (On the other hand...)
Personally I consider AF as probably the best Amiga mag overall, and the fact that it was the last of the mainstream Amiga mags to close was probably a good indicator that much of the market agreed. I definitely preferred the English mags to the American ones. Australian Commodore and Amiga Review was also pretty good.
At the end of the day it is all a matter of opinion.