I'd be all for different ranking charts for the 5 different key amounts, but there are 2 main problems with that:
1. It divides players and makes for less competition (the big one)
2. It'd be annoying on the web (either you add another dropdown menu just for mania or add a new tab for every game mode, which is cluttered and unintuitive)
Besides, you're going against the nature of how the map was naturally generated, and changing it so it's not the original map any more, just like what any other mod does. Separate leaderboards for each key amount would be like having separate leaderboards for nomod, easy, halftime, hard rock and doubletime (since each one changes how the map plays)
1. It divides players and makes for less competition (the big one)
2. It'd be annoying on the web (either you add another dropdown menu just for mania or add a new tab for every game mode, which is cluttered and unintuitive)
Besides, you're going against the nature of how the map was naturally generated, and changing it so it's not the original map any more, just like what any other mod does. Separate leaderboards for each key amount would be like having separate leaderboards for nomod, easy, halftime, hard rock and doubletime (since each one changes how the map plays)