How important is personalizing a query-letter? I.e., beyond obvious stuff like name of agent and address and writing to someone who you think would be right for your work, (I think it's obvious too, but you'd be surprised how many people get it wrong wrong and really wrongo) is it critical to actually lead off with some non-content material that tries to establish a connection with THAT particular agent. I wrote what I think is a compelling, streamlined query letter that starts (I fear) to look like a cumbersome query-letter if I beef up the first paragraph with a bunch of material about that particular agent.
You always stress a "just the facts, please" in your own writings, which leads me to believe that you might answer this by saying "get to the cool content and cut the rest of the crap." But surely there's plenty of agents out there who might be less favorably disposed towarda seemingly more generic letter even if it was a little bit longer?
If you have actual substantive content that is personal, ok.
Things like "we met at the Poodle Parade on 5th avenue and you invited me to send a query for my novel about the travails of poodle parlors".
Things like "Grandmother Snark wears Army Boots...and I know cause she buys them at my store" are funny, true, and not quite up to stalking level.
Things like "I like how you squeeze the avocados at Zabars and you shouldn't buy so much mango ice cream"...not so smooth.
Honest to dog, you do not need this. I know you think it will help, and it might distinguish you from the pack, but for every one of you who has this kind of connection, 10,000 of you are now going to obsess that you need one.
What do you need?
Shall we say it all together now?