I've been playing CoD4 for a couple of weeks now and figured I would post my thoughts.  First, let it be known that my unofficial XBOX Live nickname is Bullet Catcher (real XBOX Live ID is SpartyGuy - hit me up if you see me!).  I really enjoy some nice virtual warfare despite my propensity to be proof positive why online gaming should never incorporate physical feedback as an option - I would be hospitalized on a regular basis.  Secondly, I am a huge Ghost Recon: Advanced Warfighter 2 fan.  LOVE THAT GAME!  It is my reference for this style of "realistic" military shooter.

I was both disappointed and interested to see CoD4 would be like as it left its WWII roots.  On one hand, I was excited because GRAW2 is a bit long in the tooth now so seeing a modern military sim that really pushed the XBOX 360 platform was exciting.  But I had really enjoyed playing CoD3 despite its many flaws.  The biggest thing holding CoD3 back was also its biggest attraction for me, and that was its utter simplicity.  Two sides, a couple handfuls of weapons, and pretty much a run around like crazy shooting stuff but at the same time you could get a few tactics in play that, for me at least, increased my survival rate.  It was arcade like, but that was part of the appeal for me.  GRAW 2 on the other hand, is pretty darn realistic. Some of the maps lend themselves to running and gunning exclusively (not my forte by any stretch of the imagination) but it also allowed you to slink and sneak and be a bit more tactically aware quite often as well.

While CoD4 has great graphics and sound, I find myself feeling as if it couldn't make up its mind on what it wanted to be.  The weapon simulation is pretty good though I struggle immensely when I try and do the sniper thing - a problem I experience to a much lesser degree in the other two games.  But the biggest problem is the whole level progression and what I think of as the "magic item" rewards.  CoD4 gives you experience points as you play, and with those points and completing challenges you unlock more weapons and more importantly, more perks.

Perks are a bit ridiculous in my opinion.  For example, you can get a perk that lets you resist more damage.  You can get one that lets your bullets do more damage, penetrate through thicker walls, reload faster, automatically drop a grenade or pull out your pistol and get a few shots as your dying action, etc.  When you are struggling to make it to officer rank and you unload your SAW into an enemy to only watch him head shot you as if you were as annoying as the buzzing of flies can be a bit discouraging.  Ok, a bit of any exaggeration, but you get the idea.  I find the whole perk thing just a tad bit ridiculous and it ruins a large part of the "authenticity" flavor for me.  I'm a purist I guess.  It also creates a lot of "class warfare" as I have been booted on a fairly regular basis from games because I did not have enough experience to be considered teammate material.

The maps also seem to promote the "run and gun" mode of game playing.  Everything is city fighting and while certainly the battlefields of the real world have become predominately urban in nature, it still makes for an unreal simulation as you see hordes of people running around with automatic weapons like chickens on speed.  Granted, the infinite respawns makes life cheap, but there are a lot of maps in GRAW that reward a more reserved combat approach.  Maybe if I could find a decent perch and snipe like crazy I would be happier, but its to hard to be effective - at least for me on a lot of the maps.

I was also disappointed with the change to the Domination game play (it was War in CoD3).  Both game modes center around the idea that teams battle over a collection of objectives.  What made CoD3 so much fun was that you had to capture objectives in order to go on to the next objective. If you captured all of the objectives (with the last one being right in the enemies lap), you won. CoD 4 lets you go after any objective at any time. Whoever has the most points at the end of the match wins. I like the give and take, the ebb and flow, of War in CoD3 much better than the Domination game play of CoD4.

All in all, its a decent game - better than most probably. I have played about 30 minutes of the actual offline game so I can't speak to that at all.  I am almost exclusively a Live gamer, though BioShock intrigued me long enough to play it for several hours before sending it back to BlockBuster.  I think I  will be heading back to GRAW 2 soon, but will play CoD4 from time to time.  But my heart hopes there is a GRAW 3 sometime in the near future!!!!