You just brought up another reason why the interlock switch appears to
be my best option: the size of the generator.

Right now I have a 5500w but my daughter is building a home here and
has already indicated a desire to have her own generator as well. She's
having her house pre-wired for this purpose. So, I will eventually give
her my 5500w gen and purchase a higher wattage replacement.

Had i decided on a 6- or 8- circuit transfer switch, I probably would
not have been able to take advantage of the increased gen power of the
replacement unit unless I had switched out the 6- or 8-circuit for a
higher one (or just added a second 6- or 8-circuit switch) to allow for
higher energy loads. With the interlock switch, I can increase my gen
size to wnything I want and not worry about the panel, since the
intelrock allows me to use any combination of loads any gen I use will
tolerate.