I have a Bos end can on my '05, heck of a lot lighter than the standard can. Makes a slightly "throatier" noise, not louder, just different. Better IMHO. Mid range seemed ever so slightly livelier, but that could be a false impression.
HTH
Mark
I have a full system in stainless with a power controller and K+N filter on my 06 GSA. Top notch finish and sound and has realy made the motor responsive.
Has certainly helped the fat bavarian bird pick up her skirt and run with the rest!!!
Did not fit the Bos, it came as part of a deal I negotiated with the dealer when I bought the bike, but I have fitted a number of systems and end cans to the 1200 (check the posts, I've got an exhaust fetish) including the full Akra race system with no issues so I would have to say it is in fact the case.
I fitted mine, there were no problems, took about 90 mins in total. The only item not supplied was 2 metal o ring gaskets that go between the exhaust header and the cylinder head. Get those from your local BMW dealer before tackling the job and you should have no bother.