I love my 22, its definitely my favorite cooker. I think Weber has done a fantastic job engineering these things, and very few mods are necessary. Other than playing with the water pan, and that depends on what you're cooking, the only mod I've had to do is make a smaller fire ring for shorter cooks. I decided on half the original volume, and a little bit taller to keep a very compact fire. What I came up with was a ring that is 6" tall with a diameter of 10.7", this is exactly half the original volume. I made it out of expanded metal, so if you cut a piece 33.61" long x 6" wide, when rolled it will give you the 6x10.7" dia ring.
Here's my original post;