I have read that the 22.5's have more of a leak issue than the smaller units. Mine leaked a lot around the door and the lid the first time I used it, bad enough, it wouldn't snuff out. It was a little better the second cook and probably would continue to improve as it seasoned, but I wanted to help it along.
I ordered the SS door to resolve the door issue and the gaskets for the dome. Like I said, should be tight as a drum the next time I fire it up.
Lone Star Grillz Insulated Cabinet Smoker
Weber Genesis S-330
For info on any mods I have done to my WSM, please see this post