It will flatten your response, lower your Qtc (in most cases but it is possible to raise it if you over-stuff; this is why people say it makes the enclosure seem larger but that is not really a true statement), and it will help dampen the upper order harmonics.
It will NOT make it louder and it will usually lower your max SPL. But, due to the lower Qtc, it will help give you a little more low end.
Whether or not it's logical is based completely on what you want from your setup.