I've got the same 50-mm system as woodmanr on my 748/800. Raced it that way for several years, then moved the exhaust along with the engine and tuned chip into my street bike - no burned-out sleeves or other problems in the 6-7 years I've had them, but the stickers started peeling off so I eventually completely removed them. Much better record than the Arrows I have on my 996, which blew out after a couple years of use - I replaced the sleeves with Ti.
But in general I'd stay away from CF sleeves, it's the wrong material for exhaust systems and you're just asking to eventually blow a big hole in one of the cans.
08 Red Ducati 1098S
98 Black Ducati 748/800 (street)
99 Black Ducati 996 (race, retired)