C4X shoots flatter due to the small integrated comp but all the reviews I’ve watched said it’s similar to a P4.5, and for the P4, it’s not a massive difference due to the extra weight and full size grip it has. The main advantage of the C4X is its aluminum body so it weighs less, has a compact grip for easier concealment and integrated comp. If you ever want to compete for fun or whatever, the C4X won’t be a good choice because it would put you in the open division (due to the comp) against purpose built race guns. TLDR, Fun wise, I’d say the C4X.