A few of my thoughts:
1) This reminds me of grading papers. It starts slow, especially when you're figuring out what you're looking for and what's really important, but once you know what you're looking for, the process goes really quickly.
2) Also like grading, just as easy as it is to spot a plagiarist, it's equally as easy to spot a compelling hook and a well-written query.
3) Form rejections in this day and age (especially when agent blogs are so specific) are deserved. If you haven't done the research before you send the query, then you'll make the mistakes that will lead to rejection. You don't need a personal rejection; you need to put in some time, research what the agent wants, and be brutally honest with yourself if you're doing all of that in your query. Brutal honesty is hard. That's probably the greatest value of a good critique group (ie. bad critique group=ones who pat your back and tell you how wonderful the story is).
More thoughts to come.