Why I like V2 better than MW2
CONs: Single player lacks memorable scenes; Occasionally poor path-finding from allies.
Vegas 2, as you've probably heard, is part of the Rainbow Six "tactical squad 1st person shooter" series that started years ago on the PC. If you've played the original or early sequels, you probably remember the way-point system and the giant "combat conga" dance performed by your elite squad of soldiers that made the original frustrating and frequently laughable. This is nothing like those games.
The single player has 20 hours or so of game-play. A few years ago that would have been considered short, but compared to the newer glossy shooters, where every scene has been painstakingly constructed to give you one of those perfect bullet-time moments, or exactly recreate a famous film scene, this is pretty good. Then of course you've got the replay value, either coop with friends on the net, or on harder difficulty levels where each doorway you breach takes a minute or more thought to stop the terrorists within shooting your head clean off.
So what happened to the combat conga? Your 6-man squads of Rainbow soldiers has been reduced to a deadly efficient support team of two, and the map is now just for reference, not for drawing a battle plan that looks like a Rolf Harris sketch (can you tell what it is yet?) Your buddies go where you point them with reasonable efficiency, and are most often used to breach rooms you expect heavy resistance behind, or to draw attention away from you while you sneak around to a flanking position. You will find that, from time to time, they decide the shortest route between two points is through the kill-zone of your opponents, and the usual accidental button press will summon them from the carefully selected cover point to hover at your back, but in general this is leagues ahead of earlier versions of the game. If there is one serious issue with your mooks, it is that they are so good at shooting bad guys, you often don't want to bother joining them in combat at all. After all, if they can handle it, why stick your head out?
None of this is the real reason for buying or playing this game, however. Where this game really shines is multi-player, either versus or terrorist-hunt.
The first, crucial difference in playing this game as opposed to other FPS's in the market is the ability to hide behind cover. Yes, Gears did it, and Army of Two improved upon it. But both these games lack the precision of playing a true FPS, with all the twitch-fire and sniping potential that provides. To explain why cover is important, you need to understand how lag decides the outcome and sets the winning tactic for most other FPS multi-player.
You see, in most FPS modern games, running on a good network like XBL, you have something like 0.2 seconds between what you do, and what appears on the screen of your opponent. You then have another 0.2 seconds between how your opponent responds and what you see. Doesn't sound like much? Let's say you're watching the door in a room with one entrance (you are "under canvas", as HotLbWt puts it). Your opponent charges into the room. His system knows you're there, because you haven't moved in 10 seconds or so, so when he walks through the door he sees you on screen instantly. He's played a few hundred hours of FPS in his life, so it's a mere 0.3 to 0.4 seconds for him to go from seeing you, to lining up and pressing fire.
Now, you only see him walk through the door 0.2 seconds after it's happened, but you respond quickly, in around 0.2 seconds in fact, but that's just too late. Your friend has hit you with a head-shot, and you're waiting for a re-spawn. If your friend is really good, and your lag peaks at the wrong moment, it's possible to be killed by your mate in this scenario before he has even appeared on screen for you. Some games try to correct for this by using predictive algorithms to show where they think your soldier will be in 0.2 seconds and even the fight, but this just leads to those wonderful moments where you get shot in a doorway you never walked through, because an algorithm on somebody else's system thought you would. Also note that, even if you have no lag and your opponent has tons, he still wins - it's the total communication time between you and him that matters, not where the bottleneck is on the network.
This is part responsible for knife attacks from a fast running opponent being far more dangerous than being shot, a phenomena easily recognised across the FPS genre. In some ways it's good, because it reduces camping - nobody likes the guy who gets the "most time spent in Millets" awards - but it means that tactics, flanking and considered plans are going to come off second to twitch-shooters who charge full tilt across the map.
Now, Vegas 2 allows you to stand with your back to a wall at a doorway or corner, and see what's coming at you. You can stick your gun out and hose to take out a close charging opponent, or duck out for a quick snipe shot for those further away. As usual, level design is key, the game designers have to be sure that there is no perfect camping spot with only one entrance, and Vegas 2 excels in this department with my all time favourite maps for multi-player carnage.
Throw in the rest of the realism features, such as not being able to constantly bounce (in body armour) while accurately aiming and charging down an opponent, only being able to sprint for limited distances, and then only as fast as your carried weight allows, and interactive scenery such as ropes that can be slid down and walls that can be shot through, and you've got a highly realistic FPS where you think VERY carefully before sticking your head around a corner. Matches without re-spawn start slow and tense as the lines of battle become defined, and attrition wears down both sides, but still often end with a daring sprint to catch the enemy from behind when their numbers are thinned.
Throw into the mix the lack of hacks and exploits, a player base who broadly have reached puberty, many of which don't even trash-talk the whole session, a list of unlock-able weapons and a huge array of unlock-able clothes and colour schemes that keep you playing to get that last urban camo so your character can have a red cowboy hat, and you've got a game you go back to each time you get taunted by a 10 year old hacker who thinks he's Sergeant Barnes.
For this reason, Vegas 2 gets a full 10 from me. It isn't perfect, and the set pieces from games in, say, the CoD series are in a different league to the single player set pieces here. But what Vegas 2 does achieve is creating a FPS that does not play like any other in the genre. Twitch shooter fanatics find it slow and frustrating and go play something else, but for those of us who remain, the game is much improved by their absence.