Strafing to the side doesn't really work. You may meet someone at a corner and not know if they're going to knife you or not. Once they go into that knifing motion, it's over. It's honestly one of the stupidest additions to any game that I've played.
I don't want to waste my equipment on a blast shield. Claymores, semtex are so much more useful and I'm not going to handicap ymself because someone who doesn't know how ot shoot a gun is running around with a noob tube. They really need to nerf the noob tubes. They're perfect in Battlefield, if it's not at their feet, it won't kill them.