The 14p has more upgrade than the 15p which is minimum upgrade. Basically the leap between 12/13 to 14 brought Promotion, always on display , dynamic island, improved 48MP back camera and front camera, improved display n higher brightness.I personally wouldn’t have done it. 14P was a minimum upgrade over 13 or even 12 and just feels like an aging 3-4 year model. For $100 more you get lighter body, usb c and active button with faster cpu. Those 4 alone justify getting the new model.
While the 15p noticeable improvement is basically an “titanium”, action button, and usb c. I wouldn’t call the display nor the camera huge leap improvement since the hardware between the 15P camera (except the max) and 14P camera are the same. While both the displays have the same exact spec.
In fact the 15p is also somewhat a downgrade in terms of drop durability, curved screen, and even worst thermals than the 14P.