Benefits of Supporter vs. Upgrades

I'm not quite clear on the benefits of using Supporter over using the Upgrades plugin.

What are the monetizing differences of each and if I were to change from Supporter to Upgrades, what would be the process? i.e., what files would I need to delete in order to prevent any conflict between the two or any confusion on my part?

Not that I'm thinking of changing at this time. I'm trying to get eddicated.