Some aspects of the Leadership feat are redundant under my campaign rules, as the Entourage feat (that you picked up as a Bonus feat at L3) along with the staff employed in your businesses and estates represents your followers. However, there are still many benefits to taking the Leadership Feat.
Most importantly, you get a Cohort using the guidance (and modifiers) as per the PF description of the feat. The only change is your Cohort gets the Entourage-Ally bonuses - BUT does not count against tour roster of Entourage-Assistants, Entourage-Cousints or Entourage-Allies. When you recruit your (first) Cohort, you get 1bp free, to represent their contribution to your reputation and holding. If you used the Squire (or similar) feat to train your Cohort, this bonus rises to 2bp.
However, rather than gaining an extra body of followers, you get the following bonuses to the Entourage feat.
You use your Leadership Score (for followers) when calculating the maximum number of Entourage members you may recruit. If you already have a home base (such as a stronghold or a mansion) somewhere you get to apply the appropriate +2 bonus. So a L7 character, with a 16 cha and a base (who takes leadership) can take
Leadership score = (Level +7) + (char Bonus +3) + (base +2) = 12 : Max Entourage = (12/2) + 3 = 9 Without leadership the max Entourages would be (Level 7)/2 = 3 +3 (Char bonus) = 6.
In this case, that works out to three extra Entourage-Assistants.