I think thats the general opinion, but there are good arguements for both can setups. The smooth can with the clamp heatsink almost definitely wont come apart, but the 540c can shouldnt come apart either because of its threaded endbells. Also the heatsink on the 540c should be more effective, since the fins cover more of the can surface. The problems with the 540c are that some of them do come apart, either because of poorly machined threads or lack of threadlock, and the slightly larger can diameter can be a fitment problem on some motor mounts.