There is no point in replacing if you are looking for a performance gain as these are next to nothing, unless of course, you have experience in running a racing team, engineering skills, have the relevant software and happy to replace engine parts.
Chances are you will save weight, you will definitely have a better-looking system in place, and you might improve the note (I do not refer to noise). Most cans require a remap and there is a holy grail to be found sometimes when it comes to remapping and not having to undo the remap for the MOT. The only three cans I have come across on any manufacturer that fists the bill for sounding nice (not loud), weight saving, looks good and still MOT compliant are Remus (superb build quality and my choice), Leo Vince and Ackro (when developed with the manufacturer - Arrow also fall into this category with Triumph).
In a nutshell, it's not really worth it. The manufacturer puts the most R&D into the exhaust after the engine.