I love PS - they are very nice looking fish. I have added them to my Uncle's 2 acre pond in NJ several times which is well established with LMB, GSF and BG (until a recent partial summer fishkill). I have only managed to add maybe 20 adults over the last 5 years. We do catch them once in a great while but with all the BG already there, they may never become abundant and I have never caught a smaller one, so not sure if they are recruiting. However, being bass heavy, we see almost no baby anything living shortly after spawn. I don't know enough about PS biology/habitat but my uncles pond is red clay bottom (holds water very well), has minimal vegetation (we have tried to get stuff growing to no avail) and is not spring fed so it can get warm and also gets muddy after rains. Every place I have caught PS it was a pond or lake that had some water running through it (stream or spring) and they were always very clear water (and colder) and at least some vegetation, so PS may prefer this type of habitat over traditional stagnant ponds.
I will keep trying to stock them because I think they are the best looking sunfish. I mean next to the green sunfish (I am just trying to avoid persecution by JHAP and the GSA!)