There are many programs that can create stellar maps. But none of them reaches PP3's typographic and graphical quality. In contrast to other programs PP3 produces vector images (e.g. PDFs) rather than mere bitmaps. Therefore it is perfectly suited for creating illustrations for books or other print media. But even converted to bitmaps for web pages, it exceeds usual quality.
PP3 is optimised for the semi-automatic generation of large sets of sky maps. It has decent default behaviour, however it can be customised very flexibly. It tries to take as much fine-tuning work away from you as possible.