Depends on how you want to use it. It's a very powerful tool but I like to keep it simple.
I started using RL to add extra bezels not supported by MAME, Retroarch or other emulators. At the moment RL is powering all bezels since it has many good options for bezels and other stuff, even the choice of random bezels per system/game if I want.
I also use it for all emulators to close with "back + start" on controller, and also to hide any emulator launching windows with a quick fade in blank black screen (I don't use those fade loading screens with extra art, etc.). Also for some nice simple shaders that RL has for some emulators that don't have that (similar to bezels), among other things like several options that you can tweak per system/emulator if there was ever need for that.
Basically RL can be very good if we use it within a frame a mind that is tool that can work together with AM to give us some extra nice options if we want and without complicating things.