The important info from this IS part of the stickies. The latest firmwares (like the 6.37) aren't listed
because they don't matter. The stickies only list the firmwares worth upgrading to. If there's a firmware built off a later version of OFW with less functionality, we're not going to list it because it doesn't matter (unless you have a fetish for having a larger number in your version string or something).
And no, this is not the only guide thread on this. As soon as the 6.x downgrade came out like 5 people per forum started posting their own guides (you can see it on like any PSP hacking forum).
At least this one has more work put into being easy to understand, but it's repetitive as well.