Yes, it's better than the first.
The games brings in a much deeper story than the first one, and leaves the game open just enough for another game. Plain and simple, i feel this is such a good game that I do not want to give up really any new info on it, you just need to get out and play this game.
If you liked the first, you will enjoy and be thrilled with Gears 2. If you are curious and want to try, you won't be disappointed. Really the only reason to not play this is if you do not like fast paced action, tactical warfare, and maybe do not like a lot of blood and gore, otherwise this is one of those games you want to play and a one of those games that give you a reason to own a 360. Gears 2 is a solid game and the only spot I feel it could use improvement on, is the matchmaking online interface, sometimes, it just takes to long for one or 2 of the game types, more people are just playing the others and a few match types will make you wait a few more minutes to play.
Get Gears, join the COG army and let's kill some Locust!