RE: if upgradeability wasnt a factor........
I've always prefered the 10/22. I like the idea of being able to remove the barrel if I want to brush the bore. With the Marlin you're more likely to damage the crown. That may be a small detail, but it is something to think about. Even though I'm not a huge Ruger fan, the 10/22 has always seemed to be a slightly better built rifle to me as well.