I think it's nice. No longer can two marines, back-to-back in a vent, hold off anything but a lerk or gorge. I think it's double-edged (bad pun, yes) when fighting skulks. On one hand, you can't push them back, which is good for skulks, since their view won't be all shaken up. On the other hand, this allows you to run straight at a skulk and get two quick slashes in where you would otherwise only get in one if it was b5. Then again, the skulk can still bite you while you do that. However, I have noticed that running at a skulk and just knifing in his face tends to work if he's slightly weakened.