TSRM because it gives better performance supposedly. And also, you won't have to worry about any rusting or welding issues that the HKS have been known to have. Although I have never had a problem with my HKS, some people have. If you get HKS, get new one with the silencer hole and HKS engraving on the tip. Power-wise, you can feel it just don't expect it to be like shooting 50 shots of nitrous into your port, it's just an exhaust.
