Haven't played Gears 3 yet and i didn't get to play the beta. From what i know though, the sawed off destroys at very close. I assume the gnasher performs similarly to previous gears. I guess gun fights will be more interesting now there is another alternative
close range weapon.
Woops only just noticed I put gears 2 on my orginal post, silly me, and yeah it does destroy at close range and people can get the wrong impression of the sawed off by thinking its unbalanced compared to the gnasher at close range, but it really isn't as
you only get one bullet before you have to reload, and the reload is really slow so it balances it out.
Not a fan of using the Sawn-Off myself, lacks the versatility of the Gnasher. Played a few games against a guy who was really good with it though. Now I look out for people using them and just avoid letting them anywhere near me.