I'm looking forward to Pathfinder and I usually love the stuff that Pazio does. However I never been a fan of any of their art. (Thats sortof inaccurate, generally monsters are cool.) However as soon as they do something resembling a PC ... gah. I like my armour to vaguely look like armour that's historically accurate. I like people in surcoats and chainmail. I like spellcasters in robes that cover a large proportion of their skin. I like weapons that seem a resonable size for the character to be carrying.
There's something about the core book cover that I find very compelling, but the PCs details just ruin it for me. In a lot of ways i like the simple evocative black and white art of OSRIC and some 1st edition products a lot more. One of the reasons for this is I can use these illustrations an say here's a sketch your characters are shown of X monster, or here's a tapestry you find in the keep,dungeon etc. Maybe its just that simple inspires imagination, whereas a 'snapshot' (type of art) doesn't, in some ways it seems to limit it.
I guess I'm the first major criticism. I do find the Bestiary's cover quite compelling.