In Aces High, the "massively multiplayer" online combat flight simulator (which I was into big time until my expensive joystick crapped out), the different models of Spitfires are given different point values. The Mk I was given a value of 40, while the Mk XVI was given a value of five. This meant that if you bested a Mk XVI pilot with a Mk I, you would be awarded 8 points, but vice versa, you would only be awarded 0.125 points. As you might expect, the Mk I was a dog compared to the Mk XVI.
Often looking for a bit of a challenge, my favorite was the Mk IX. If I wanted even more of a challenge, I would take up a Mk V. However, few people used the Mk I outside of historical scenarios like the annual Battle of Britain setup.