If you do not have an FAE we recommend baffles in the muffler replacement. The muffler replacements with baffles (but no FAE) will have a deep throaty sound, similar to older Nautiques.
If you have an FAE, muffler baffles are still an option. We have customers with an FAE and the hollow tube mufflers that say their boat is exceedingly quiet. We have some customers with FAE and the muffler replacement with baffles who are also very pleased with the noise reduction.
At this time we do not make a recommendation on which is quietist. Please let us know how quiet your installation is.