some of you guys seem like you are talking about normal mode seigecrafter? Which was pretty easy imo, took us 3 attempts, including a first one where we were just "let's pull and see how this goes".
We've spent around 7 hours on garrosh now though and still can't get it. The only other fight in SoO so far that took more than 3 attempts for us was Thok, which probably took around 6-7.
So yeah, even though 7 hours on garrosh isn't as many attempts as it could be on some fights since it takes around 8 minutes per attempt to get to the point of wiping, imo it's definitely the hardest fight of SoO by far.