I just played through the entire thing in one sitting. Took just under 5 hours. It was way more fun than either the original Crysis and 2 (haven't played 3 yet). The third person cutscenes were much more enjoyable than the first person ones in the first game and it felt much more action packed which was more enjoyable to me. Psycho is a more likeable protagonist than Nomad too (Nomad barely felt like a character at all). The difficulty felt perfect and the game didn't overstay its welcome either. The game still looks great too even after 5 years. As you can probably tell, I loved this game. Really impressed and actually pleasantly surprised with how much I liked it :)
Warhead was the best mix of open combat and larger areas with more structured levels and storytelling. Crysis 2 and 3 went way over board with it and its no secret that the first game fell apart with its storytelling parts in the last 1/3.
I also always thought the hover chase w/ the kickass music playing was the best "scripted" sequence in the series.
Currently playing: Batman: Arkham City - Assassins Creed IV - Resident Evil: Code Veronica X