Keep in mind that the serviceable cans normally will not have as good as sound performance as a sealed can.
I've heard this stated before, but haven't necessarily found it to be true in actual experience. We purchased a DB meter this summer and ran comparisons on several cans, and found that in some cases the serviceable cans were actually quieter (for example the sealed Osprey 9 we tested was louder than a full serviceable Octane 9 HD). Take a look at the sound testing and reviews section on Silencer Forum
and you'll see several examples of the same findings. So it really just depends on the individual can.