I agree wholeheartedly that it is the best. My undergrad is renowned for its horrendous physics department -- averages on an open book test for my class would generally fall in the 40s. Even though I pulled off a miraculous 72 average and earned an A, I came out of there feeling like I knew absolutely nothing about physics. Nova does a great job of giving content review so I feel like I am actually learning the things the prereq class was meant to take care of. I personally am liking the discretes -- I feel like they help me get the content down before I try to do the passages, but then the passages come along and I actually understand what is going on. I don't know how my MCAT is going to turn out but hopefully this will boost my score from the 2 I would have otherwise gotten!
I can't compare to any other books because I haven't tried them. I do know that Kraplan is, well, crap... I read the first few pages of their premier review book while in the bookstore and even my non-physicist self could tell there were lots of mistakes.
Hope this helps, I HIGHLY recommend!!