You need one of each, a hack plus a 2 wheeler. I have a GS plus a Ural Retro, find myself taking the Retro everywhere but if I need to get somewhere or have some miles to cover I take the GS.
I see from another thread you're planning on hitting the BRP soon, PM me. I have a place near milepost 199 (US Hwy 52 and Fancy Gap VA) and if I'm there you can try out the retro on the BRP - a road and speed limit perfect for a Ural.
A GS with a tub sounds like a winner to me.