Going already too...have had GA tix for a few months.
I went to Sting in the seated chairs and they were just terrible, to be honest. Not very comfortable at all. When it started, people would stand up and then EVERYONE had to stand up. Just wasn't enough room between rows to ever be comfortable. I vowed NEVER to spend the extra coin to upgrade to them from GA at Sandalford...
...then again, for the same $$$ as GA I would definately consider it!