I wanted to avoid the comparison because they are such different bikes but since you asked, here we go but first let me ask you Boricua, what does "one of them" mean?
First off the 800GS is oriented towards off road use as the V is street only due to the tire configurations and such, long suspension does not mean dual purpose. I used my V at the end mostly for commuting and since the swap, found that the 800 does the same and in certain circumstances even better.
I don't knock the V one bit, I liked it very much but I just like torque and the bigger engine on the 800 gave me that and other options the V did not.
Hope that helps a little.