Aptitudes in Only War basically emphasize your class by applying restrictions to how you spend EXP. Has anyone tried removing them completely? Our group has been doing this for an ancient-Rome style game we've been playing with the Only War system. There are two main effects.
1. You can updgrade whatever you want (obvious)
2. Vastly easier to understand the game system. We've cut book-referencing down by about 1/2 and it's much easier for less system savvy players to build characters.