I had a 9-night stay at the PH Seoul and I checked out early to go to the GH Seoul after 2 nights. I liked the GH a lot more than the PH.
The PH is certainly nice enough (definitely fancier than the GH) but everything about the hotel is just a massive hassle. Not something that I want to deal with when I'm on vacation. I hate it when staff at "fancy" hotels feel that they are doing you a favor by letting you stay there. I was very happy to get out of that place.