Recycling actors only improve performance through constant destruction and creation because it doesn't fully remove the instance of the object from memory. It works by checking a list to see if any actors exist in the list, if they do it then takes one from the list, if they don't, then it creates a brand new actor.
Regardless of whether you are using Recycled actors or not, the fact that less actors exist on screen at one time will increase performance. Even though you may not see a change in FPS it does increase performance. It is either a small gain or a big gain depending on the type of game that you're creating, how many different actions are going on at the same time, and how many actors have collision bounds.