Overview: Pylons are for the AI NavMesh and they are pretty usefule but there are static ones and dynamic ones,
Doubts: Is there somehting i have to know about dynamic pylons before using them ?
Advantages and not advantages ?
Cant help much here.If im not mistaking the dynamic ones are not explained in the UDN documentation.I did made a test with a dynamic one early this year.I had two rooms and a wall + interpactor door between the the 2 rooms.Animated the pylon in matinee to move from room 1 to room 2.In room one i have crowd agents that coudnt move through the door.So i made a key pressed event and when activated i open the door and the pylon was moved to room 2 and the crowd agents managed to follow with no problems.
In terms of pylons,the best thing i know is that after every tweak you do to it,or the AI or something related,you have to build the paths.The thing is that the paths get broken and you dont get warnings.So before every test you do to a level, remember always to rebuild paths!! The same goes for the final game build.Your final step shoud be to rebuild paths>and than save and cook the level or you may get strange behaviour from the AI.
And you shoud use the recast option from the Pylon properties for better collision check.(depending on how complex your level is)