I do realize how reaction time comes in to play with that, but not overall skill. Skill, to me, is when one has to think a lot and judge what's the best to do. In CoD, that's mostly something like "Go prone or not?" "throw a nade or not?" Cuz one's dead within half a second anyway. Plus, ping very often decides who's the winner in this kind of game. Except for when you're in a LAN or similar. I mean... seriously, how hard is it to aim? that's basic. Learn once and you know it, there's no difference between different situations, or not big enough to mention anyway.
In crysis on the other hand, you have a lot of choices to choose from. Go prone? Jump up high? Do a circle jump around him? Throw a nade? Fire a gun? Flee? Punch? Guess you can come up with much more. EDIT: Not to mention 'I'm going in there, how should I configure my weapon? Sniper scope, reflex or iron sight?' etc.
Cause you have time for so many more decisions. Plus there's a bigger variation of weapons imo. The cod weapons are basically all the same in hardcore mode. Just that one fires auto and the other semi.
One thing I think CoD has the better end of is the use of sound. I can hear people running from way away, though it's easily confused by other sounds going on in the game which makes everything a bit more exciting. It's hard to use sound as effectively in a game as crysis though, which is so fast paced, so I don't blame crytek for it. The sound quality in crysis is excellent, which most sound engineers agree with.
Here's how long it takes to kill someone in crysis;
The SCAR fires 11.666666666.... bullets a second. If aimed right, which one does up till 20 meters at least, the enemy should therefore die in a little bellow ½ second after the trigger is pushed, as 5 shots is enough to kill a person, if he's standing still that is.
Another thing crysis has got right - community. Jebus, I've never seen a community whining as much as the CoD one. "Lucker" "noob"... I mean, it goes on for eternity. Not saying there aren't those who are nice, but they're rare. In crysis on the other hand - Join, have fun with everyone. Much more of that. I know, there are whiners in crysis as well. But that's in a game with an insane higher learning curve, way less compact technically (much better/more advanced technology though they aimed a little high to get it together totally functioning) so they have much more to whine about - yet they don't.
I'm way more experienced in the Crysis community though so not 100% sure.
I like both the games, but I still think CoD is the simpler one. You have way less things to keep track of at the same time and less options to choose from. For me, options is what a game is all about. That's also why I totally hate the CoD series singleplayer - Sure, great story and all, but I want to experience the story my way. Options and a great community - those are win for me.