wishinfishin -- Do you have a Bass Pro or a Cabelas near you? I stopped by my local Cabelas and played with the resolutions and different models for over an hour before I made my selection. From the "Preview Mode", you can change the frequency through the menu system which will allow you to see the difference between Standard Definition, High Definition, and Mega. I thought there was enough difference to warrant spending the extra for Mega, but to each their own...I know many people would tell you to pay the extra for the 10", but I could not see a difference in resolutions between the 9 mega and the 10 mega. I guess it is just how your eyes see it!
I think the Mega would be nice for you when you are in the river, bays, and the lakes. I do not think it will be that much help when you are on Lake Ontario or the St Lawrence due to depths.
--Joe