no idea if that brand works, I think they are pretty big brand with reasonable reputation, looks similar build as the others but £140 not £740. Bear in mind the technology is nothing, just a tube and a perforated tube inside that. The silencer costs 20 quid plus a few bends and end caps, so all in to make an Akropovic is less than 74 quid !!!
its possible its as good or better than the others. Also possible it doesn't help or even drops the power. Most likely slightly better than stock in most of the rev range and a few bits missing in others (just like the very best).