I think it's just an individual thing. My p14 male was the most active top/middle swimmer but all of the rays I have now come to the front when I approach and actively climb the sides, forage for food, top each other etc.
i would say p14 have been the most personal stingrays i have owned. they are always working and searching for food. if you have sand they will make a sand storm rummaging thru it. they really have a way for pouncing on food too.
Fishdog's lady Jag used to reside in my pond. That girl got keen on associating noise in the basement with being fed. IF she heard me down there doing laundry or anything and she didn't get fed she would sit there and spit water over the side of the pond till she got fed.
My Falks behave very similar to that Jag. They seem more active then all other rays I've kept.
Ahh the spitting thing. My bd female used to spit water 4.5' straight up and splatter the ceiling when she was in a floating pup tank. My bdxhen has now taken to the spitting. My least active Ray I've ever had was a pearl but I'm guessing not all pearls are like that.