How expensive is Mecanim?

So, Im using Mecanim to drive the animations on the main character of my project and that’s working great, but now Im wondering if I should use the same system for the enemies or use the legacy anim system to save resources.
The good thing about using mecanim for my enemies is that they can use the same Animation Controller and most of the code logic, but I dont want to do that if it ends up being way too taxing on the system.

Any thoughts?

It abolishes the need to spend expensive development efforts to integrate 3rd party middleware.

I guess, but I was wondering how taxing is performance wise, I didnt mean expensive as in money, but performance.

did you ever come to a conclusion on this? I’m faced with this question right now.