Does anyone have any data on which of the following mods produces better performance, and which mod is quieter?

Akro slip on exhaust with stock cat
Stock muffler with de-cat pipe

TIA

I have had a Austin Racing pipe with decat and loved it, but it is on the loud side. A friend just did a decat with the stock can and it is very nice, deep rumble but not a cop magnet. Have not heard a Akra can with cat but I would say it would be the quietest. Getting rid of the cat will give the best power.

Exactly as mentioned above keeping the stock cat will be the quietest setup, its pretty much pointless buying any muffler to fit after the stock cat so it is a huge waste of money buying an expensive one, best option for the budget is to fit an Arrow, Mivv, Remus or similar decat link pipe

Also have you tried running just the stock cat? remove the stock muffler & go for a ride just to try it out, gives you an idea how little the stock muffler reduces the sound, it is mainly the catalytic converter that does most of the noise suppression

The Arrow (71613MI) link pipe with a resonator sounds good with the stock muffler

While I agree with the fact the stock cat is the biggest inhibitor of volume and free flowing air, there IS a difference in sounds and volume between the various slip ons. They all have different lengths and sizes and internal capacity and that all has an impact on what happens higher up the system. The bike is louder with an SC CR-T or Titanium Pipe Werx slip on than it is with no end can and just the stock cat. True story.

Would love to see the actual soundmeter results, I am an automotive exhaust fitter/welder myself, not a scientist but logic will tell you putting anything behind the stock cat even if it is a baked bean can much like the SC CR-T mufflers with even the slightest bit of packing & baffle tube will affect the sound & flow etc even a tiny bit but for it to actually increase the decibels....that I would love to see
(if either of them actually did that I would throw them in the bin as they are not really any kind of muffler if they increase decibels, they must be fooling us all???)

So what you are saying is.....I can run my 1290 with the stock cat, remove the stock muffler & go for a ride with no muffler & purchase either of the SC-Project or Pipe-Werx mufflers mentioned & fit them on the end of the stock cat & it will miraculously defy the whole point of R&D etc & the basic logic involved with manufacturing mufflers & they will actually make it louder than riding it with just the stock cat?