The Exodus is perfectly fine as a weekend pack, heck even overnighters. Why?
It compresses really well and you can decrease volume using the clips located at the bottom of the pack. Is the Exodus the ideal short trip pack? Maybe not, but depending on your kit and locale, it may very well be a great all around pack for you that covers summer trips and winter bulk loads. Throw in your kit and dont sweat reducing bulk so you can fill up excess volume, thats a simple way to improve the carry of the pack.
My father in law is a lightweight packer, he owns a Super Exodus and takes it with him on every trip, whether its an overnighter or a 5 day trip loaded to the gills with all the food he insists on packing in. It sounds like the Prophet may be the better option but I can't make that judgement, you know what you need.
You wont "wow" anyone with a tiny SUL pack on the trail but who cares?
Function, function, function.