How long is GoW 4?

I'm curious to know, just how long is God of War 4? I've heard great things about the game and am eager to dive in, but want to make sure I allocate enough time for my gaming sessions. Is it a short and sweet experience, or will I be immersed for hours on end? I'm hoping for a detailed answer that takes into account the main storyline, any side quests, and perhaps even replayability. Thanks in advance for your insights!