Alright, so I just broke my own rule of not buying the "Riffs of Good Movies" because my cousin, who's both a huge MST3K and Memento fan, heard about it and really wanted to hear it. So.
I had some chuckles, I will admit, but both me and my cousin found ourselves drawn more to the movie, and none of the jokes really stuck. I finished watching it a half an hour ago, and I can't remember anything beyond "A lot of Joey Pants jokes, and a running gag about a dead raccoon that I kind of wished you kept going because this is the only movie you could pull it off."
It wasn't painful or nothing, but it wasn't amazing.