A can without a baffle in theory may release a couple of extra HP. Some cans release more than others, and to get the full benefit you want to have it remapped if its a K3+.
It may cause an issue with your insurer - some are bothered about aftermarket cans, and some don't seem to mind. Some people tell their insurer, and some don't.
If you have a crash & Mr Plod thinks it may have been influenced by 'excessive speed' then your insurers may cite the new can as an excuse to invalidate your insurance - and that's even without being restricted to 33bhp, so I suspect your insurers might jump up and down a bit
It's worth giving them a call just to check - at least you canthen weigh up the risks
