What worked
Destruction 2.0 is amazing
Bad Company 2's "Destruction 2.0" system lets you do everything from shooting fire holes through cover to completely destroying structures and watching them come crashing down in the most convincing manner I've seen on a console to date. If you're taking cover inside a building, a tank can completely obliterate the wall you're hiding behind with one blast, so you've got to be smart and know where you're headed next. It adds a unique element to the "Rush" multiplayer game type, where you have to plant charges on objects in buildings and stop the enemy from defusing the charges. You might be tempted to level the building to wipe out some defenders, but where are your teammates going to hide when they're planting and defending the charge?
Tactics and teamwork, not twitch
Only the most elite players will be able to survive for long on their own, and a team who actually plays like a team will always win over a bunch of lone wolves trying to rely on their reflexes. You can "spot" enemies and they'll show up on the maps of all your teammates, the assault class can drop ammo for their teammates, medics can drop medical kits to heal or use defibrillators to revive their fallen teammates, and engineers can repair damaged vehicles - and in all of these cases, you're rewarded with experience points for doing so, which means many people who otherwise wouldn't are now playing like a team.
Grounded in reality
While you unlock extra weapons and gadgets as you progress through the ranks, there's no "perks" that allow people to perform logic-defying (and ultimately fun-defying) feats like running around stabbing people from ten feet away, which is in stark contrast to Modern Warfare 2. (There's also no kill-streak rewards that give the players who are already dominating the match additional high-powered ways to keep dominating.)
Dedicated servers
EA's long-running arrangement with Microsoft means that Bad Company 2 (like all EA-published games) can use dedicated servers. This removes the "host advantage" problem found in every non-EA shooter to date and offers a far more level playing field. Having said that, I have experienced intermittent latency/lag issues - just not in nearly every single game, like the competition. This makes me think that there may be a limited number of servers in countries outside the US, and once they're full, you'll end up on a server in another country with less-than-ideal latency. I contacted both EA and DICE to ask where their servers are, but had not heard back at the time of publication.
Unmatched scale and depth
There's only four game types across ten maps, but they're all unique and highly tuned. There's 15 vehicles on land, sea and in the air, including several different tanks, boats and helicopters, an ATV, a Hummer, and a controllable (and lethal) UAV. Unlocking new gear is a slow but steady process. The maps are truly massive, and will take a very long time to learn inside out. And of course, I've already talked about how much the Destruction 2.0 system adds to the gameplay.
What didn't work
Voice chat only for your squad
You can only use voice chat with your squad, which is a maximum of three other players out of the 12 on your team, and quite often, no one. As a result, most people end up using Xbox party chat rather than in-game communications. This means that if you're not playing with friends, you're not likely to hear anyone, which creates a lone-wolf dynamic that almost every other aspect of the game is set up specifically to punish. Not being able to communicate to a teammate that you're an engineer who can fix the badly damaged tank he just drove past you at 40 miles an hour is incredibly frustrating.
No effort to balance games
I've seen a team of ten with three people around level 20 (which I'd guess to mean something like 50 hours of play since the game launched last week) go up against a team of ten with eight unranked players (which means they've played for less than an hour). They were unsurprisingly beaten swiftly and without a challenge. I've also found myself on a team of two, against a team of four. The servers made absolutely no effort to add players to our team while we were unrelentingly punished by the other team for 45 minutes.
Throws players into the deep end
The campaign isn't nearly enough training for the multiplayer games. As my friends buy this game and jump online, the first question is always "what's going on?" (and not as in the "how are you?" version of the question). It's clear that many players still have no idea you can actually defuse a charge once it is planted by the enemy - and with the voice chat issue I mentioned above, you can't even tell them. Helicopters in particular have a learning curve like a brick wall - every time you're on a level with helicopters, you'll see at least one teammate jump in, fly for a couple of hundred meters and crash spectacularly into a mountain or building. A couple of training scenarios that you can run through offline would be a big help.
Issues with servers
Over the weekend there were extended problems with the servers, originally with PC and PS3, then on the 360. I'd hoped that things would be smooth sailing from there, but last night I experienced the dreaded "Cannot connect to EA Online" message again. It does seem odd that EA and DICE ran a beta over several months, and a multiplayer demo for the Xbox 360 and PlayStation 3 that saw 2.5 million downloads, but are struggling to keep up with demand.
Spawn camping is prevalent
If you're not familiar with the lingo, this means the defending team can sit in the attackers base, where defenders reenter the game (or respawn) after being killed, picking them off as they respawn. It's annoying enough before a team of four playing against a team of two start doing it. This would be incredibly easy to stop, with an existing game mechanic (you can't leave certain areas of the map at all times, or you'll die after 10 seconds).
Worthy?
If you're into online warfare, you simply cannot miss this game. It's that good.
If you're relatively new to online warfare and don't have friends already playing who can show you the ropes, it might be a little tough to get started here, for reasons I've already covered.
If you're only looking for a fantastic single player campaign, you might be a little disappointed. I wouldn't say it's been bad at any stage, but it's missing some of that edge-of-your-seat factor present in other shooters (including one that it has unashamedly borrowed from). I've only gone back to it once after my initial session, and that was when the multiplayer servers were down. (Looking over the review excerpts at Metacritic, it appears I'm not the only one that's found the single player campaign a little lackluster.)
If you've got access to multiple platforms and can't decide which version to go for, DigitalFoundry has a stunningly in-depth look at the differences between PC, Xbox 360 and PlayStation 3 versions of the game. (They also perfectly sum up my thoughts on Bad Company 2's 30 frames per second versus Modern Warfare 2's 60 frames per second - a gaming experience of this magnitude simply could not be achieved at 60 frames per second on this generation of consoles.)