To be honest I think the best site for advice on that type of topic is creditboards.com, where they have lots of resources about credit and mortgages. Credit Scores do have general guides to the % value of the credit data used in your scores. How your score is impacted by certain changes in your credit data still varies person to person.

I would say that when it comes to credit cards Flyertalk is a good resource but you should still cross reference with other information that can be found on creditboards. Together they may provide you with a more complete understanding of your situation and it never hurts to check another resource before making any decisions.