They have a very different feel. GMG actually modifies the text slightly when it refers to garfield by name and is basically the story of a guy going crazy talking to himself. SG just removes the Garfield lines and answers the question "What is Jon's point of view actually like in Garfield?".

This article is awesome, by the way. I was so addicted to dealing with garfield strips programmatically a few years ago. I wanted to work on a library which could analyze the images, reconstruct the layers and extract the text in order to do things such as removing specific characters, lines, randomizing extracting every single Jon/Garfield sprite and constructing animations out of it, etc.

I feel like Garfield is actually a very cool platform for this because there is a lot of data and not a lot of variations (garfield is extremely formulaic). Maybe this inspires someone to work on it.

(PS: Hint: If you are interested in working on it, scraping every garfield strip off the official website is extremely easy)