I use Performance Tire as well. HOWEVER, when they did my alignment, they used erroneous specification values for the alignment that they had stored in their computer, instead of the copy that I handed them from the owner's manual that listed the actual specifications. I had to make them redo it. But, once they used the correct values, all was great. They even let me sit in it while they aligned it so it was weighted properly.
So, just make sure up front they use the right alignment specifications.