I've spent so many hours going through IR's, I finally got fed up and just picked one that came closest to the sound I was looking for and used EQ and advanced parameters to get it to where I wanted. I was spending more time trying IR's than playing, and that's not good. It's totally a matter of personal taste, but I've never found one that I thought sounded perfect, with no tweaking required.
This is more or less the methodology I've been using lately. I don't always go wit hthe same IR, but I have maybe 10 that I cycle through and pick from.