Nibiru,
I checked out the site that you recommended and downloaded the
SG TCP Optimizer. To be safe (rather than sorry later) I made a backup of my default settings, then allowed the program to automatically optimize them, just to see if there was any noticeable difference afterwards. I may try to manually tweak both the RWIN and MTU settings later.
I'm happy to report that there seems to be better data flow .. for now. I know that most of the connectivity issues still lie on Verizon's end, as an inconsistent signal from my provider is still the crux of the problem, regardless of whatever tweaks may be applied to help improve it.
Thank you for the recommendation. It seems to have helped some.