The things Gears 2 does better than the first are in vain because of a few flaws.
The main area GoW2 trumps the first in every way is the depth. All the new gameplay features make the first game feel completely outdated. The game has a much better offline multiplayer component. You can now play with bots in two-player split screen, in whatever mode of your choice. The new Horde mode is also a big draw for the game. There isn't much I can say about how awesome it is to have five buddies teaming up and planning against seemingly endless waves of Locusts. The new War Journal feature also adds a very convenient tracking of the Collectibles you've found (something that would've been great for Cog Tags), achievements and characters unlocked, and leaderboards.
The multiplayer modes are better as well. Many returning from the original, new modes like Wingman add a brilliant kind of fun to the game. Instead of two teams of five people going against each other, Wingman pits five teams of two people all fending for themselves, aside from the player and their specific partner. It's very well done, because instead of the last group alive winning, your kills get you the win. Wingman is personally my favorite mode in Gears of War 2. However, something else I enjoyed very much was the Campaign mode. Where the first game had a relatively short story mode (Finished in two days) that was difficult, the sequel has an all-around easier, but more satisfying Campaign. The levels have more variety, it's way longer, and the story will have you much more genuinely interested than before. It feels like an actual war this time. The feeling of there being a threat and being loss is very present.
However, the main flaw here is something that brutally affects the quality and lasting value of the game. Originally, Gears 2 feels like an amazing superior sequel. It plays better, it has more meat in the sandwich. But the quality that keeps people playing Gears, that being online play, is extremely messed up in the sequel. There are issues with matchmaking speeds. It has taken as long as 30 minutes for me and a party of friends (basically cutting half the work off by being in a lobby) to find another team to face. We don't have any restrictions on our internet connections, the game just has dodgy matchmaking. The connection in-game is also problematic. The main issue however, is balance. The gameplay is superior in a general offline, campaign or horde environment. However, in a competitive online environment, there is a serious issue with how the weapon balance and tactics due to changes or new additions, and more questions must be drawn from the fact that it has been patched four or five times, as a failed remedy.
All in all, Gears of War 2 is a very good game. But playing it online is easily the most frustrating experience I have ever had with a multiplayer game. The sad thing is that it is so popular that people will play it just because it is Gears of War. This has separated the fanbase very greatly in who plays which Gears game, and I can only hope that when the time for Gears of War 3 rolls around, Epic Games gives us a fully finished, polished, and balanced game. It would be much better than getting a rushed, glitchy, patch-needing game. Especially when the patches hardly fixed anything.