Just a thought:
I have set the avatar max size to 160x160 pixels. Let's say, I do upload an avatar sized 640x320 pixels. Then your extension will resize it to 320x160 pixels which is totally correct.
But what I would love to see is an option to choose the resizing method. Either just to 320x160 px or to the exact maximum avatar size of 160x160 px. And if the aspect ratio is not corresponding to the one of the max avatar size set in the ACP options, then to cut out the middle part of the image.
So basically upload 640x320, resize to 320x160 and cut out the middle part to make it 160x160.
I hope you understand what I'm thinking about.