I know there are other threads about this issue but they seem more direct towards H Sha and other T14 encounters, so I thought I would make this one for the new patch.
I didn't do Heroic Sha and did not seem to have the issue on Heroic Amber-Shaper but on the first day in ToT the issue of stampede of causing immense lag for some of my fellow raiders did begin. The lag did not happen to me specifically, but on trash and on the first two bosses my guild leader and a few others did whine out that they were freezing up when I used stampede. After that I just did not use it for the rest of the night and we had no problems. I really wanted to make this thread to see if others had similar issues in ToT and if they had some quick fixes. Thanks.