Having the mod installed on my own site, I have the option to select my thumbnail size, my product page size, and my popup (detailed image ) size.
Its honestly probably one of the best mods out, and EVERYONE should have this installed.
I simply have to Make my detailed image (I use 640x480 on my detailed pop ups), upload that pic, and it is done.
Its like a Ronco Rotiserie...."Set it and Forget it"
And to be completly honest, its actually made my page load times much quicker.
Check it out.
www.ridequality.com