Lets make that clear.
Loud exhausts can turn someone, that is not opposed to sleds, into a 'greenie' on the topic of snowmobiles real quick though. Most aftermarket exhausts are borderline obnoxious (or full blown)... the less expensive ones especially....even more so as the packing burns out and it is not replace. There are more cheap exhaust sold OR turbo systems without mufflers than quiet units.
If your extra 3.8 hp comes at the cost of me loosing my priveledge of snomobiling in the backcountry... the choice is easy for me.... and it should be for you too.
Race pipes don't belong on the mountain, IMO.... unless you can make them sound reasonable.
And.... Snowbilers are still looked at like the Koresh Branch-Davidians of the backcountry world by the public at large.... those things that stand out like littering, loud exhausts, sleds that are out of tune and belching smoke, destruction of property... all these little things that can be fixed easily are going to give us the same fate a the Waco group if WE dont fix them.