When I was introduced to IE a while back on a GB I started, I have a lot of respect for the company, Jeff Ireland, and the products. I met Jeff when I went down to pick up some of the parts from the group buy and I was very impressed by his knowledge of the cars, and the designs of what he had in the works (his shorty headers finished prototype).
I'm personally very satisfied with the strut bar and 325i cat-back that I purchased. The muffler is a little throatier than stock, but not annoyingly loud. It's about 10lbs lighter than stock and completely stainless steel. Something that no one else in the market is currently competing with for such a good price. As soon as I finish with my current motor swap, I will be getting a set of the headers as well.