Hi.
Performance wise it might not matter in a build, depending on your setup.
For editor it can be better performance (especially in pm version 1.9.0 and below) and readability.
In our game, for our player I did not use much run fsms yet as when i started on him 3 years ago i did not have a lot of knowledge of the power from a Run Fsm.
on our enemies i use a lot of run fsms now.
For example, I have a fsm for behavior (patrol, attacks, got hit, stunned etc)
on my patrol state I have a template to do the standard patrolling, then a template to detect player (and send a attack event when player in range) in front
and a detect player behind.
These only need to happen during patrol and in some other cases (double attacks/ combo attacks).
if i would use a separate fsm, i would need to send a start/stop event to the detection fsms as they should not keep detecting since they use boxcasts(raycasts)
and if you have many enemies doing those i can start to have lag.
With a Run Fsm I can just place it on the states that need the detection, also i can re-use them on other enemies.