I have used four developers:
D-76
XTOL
HC-110
Diafine

Started out using D-76. In fact, when I started out, when somebody said, "Developer," they almost always meant D-76 diluted 1:1.

I learned to use XTOL, just a couple of years ago and I like the results. In fact, now, XTOL is pretty much my Go-To developer. I still use D-76 because it's what I learned with. However, I like the results XTOL gives me.

I have a bottle of HC-110 in my cabinet, just because. It keeps forever if you make sure the lid is on tight. I'll always have it if I need it.
I use it occasionally but I know XTOL and D-76 better.

Just got a batch of Diafine and I like the results I have been getting with it but the jury is still out. I probably will keep using it but XTOL will probably still be my favorite. Only time will tell.

Best advice: Pick one and use it until you understand it well before trying another. If D-76 suits you, there's nothing wrong with keeping on using it.
I don't know much about Polypan F but, that aside, if you would like to experiment with different developers, XTOL is probably a good place to start.