I bought one and it arrived last week. I think it looks awesome though the welds do not look as perfect as those on the Challenge x-pipe. I will know more when I test fit it, but this is really a very, very simple exhaust in the typical V8 style with mostly long straight piping, so I do not expect any problems and any that do arise should be easy to fix. I am a bang-for-the-buck person so I do not have a "more powerful sounding" rear exhaust that sounds great but adds little to no power, which means I will be adding resonators to the x-pipe. I bought Vibrant resonators that have not yet arrived. When I cut the x-pipe to fit them, I will be able to massage any fitment issues and also inspect the guts of the x section of the x-pipe and clean up any rough internal areas with a die grinder.
I am going slowly, so I do not have an x-pipe tune yet and will probably not race off to the dyno. I am waiting for the Vishnu meth tune, since I think these cars are octane and IAT sensitive and having the equivalent of race gas with colder IAT year round should really help power. I think the meth tune will help many people break the 400 rwhp barrier that only a very few have broken thus far in naturally aspirated stock displacement form.