I am building a site where users are given permissions similar to SO. I am working with two models.
The first model assigns roles to users based on points. I can probably use Rules or a build a module for that. The nice things with this is that I get to use Drupal's build permission system. The downside is that I probably have to setup +10 roles and add even more if I want to give new permissions.
The second model is based on a custom build module (not build) that checks if a user is permitted to do whatever he/she intends to do. In this way all the roles can be avoided, but it doesn't use Drupal's permission system, which makes me a bit uncomfortable. On the other hand, there is no need for many roles.
So, is there a performance hit on having many roles? Other problems?
Any thought on this? Other approaches to give users permissions based on user points?