Originally, you were able to do FF Block to move forward quickly. Now you have to do FF Block, F block, F block, F block. If you attempt to continually do FF block, FF block, FF block; you're actually vulnerable following the initial FF block and have to use F block. Go online and have a friend just continually throw Noob's tackles, Sub's iceballs or Smoke's smoke bombs at you on the opposite end of the screen; you'll figure it out pretty quickly. The dash nerfing was made to create more space for zoners.