I spent 40 years as a cop in a major metro area. And, I can tell you that the local cops think any federal officer, i.e. FBI, ATF, DEA, ICE, etc., are a bunch of buffoons. Yes, they have the best equipment, latest gadgets, and overblown egos.....but insofar as actually being cops....they aren't and never were worth a hoot.
Local cops laugh at them behind their backs. We only used them when we were forced to or if we needed some additional people for something.