4-inch or 6-inch?
 

Considering the Ruger GP-100 (for the purposes of toting around in the woods for rabid skunk protection), does the 4 inch barrel shoot as well as the 6 inch barrel to make the extra 2 inches worth it?

You'll have to try them yourself, I'm afraid.
I shoot the 4" better than the six, even though there is a theoretical advantage to the longer sight radius. Although I never tried the full-lug 6", only the full-lug 4" and the half-lug 6".

I'm partial to the 4" barrels myself. Makes packing it a lot easier. You will lose some velocity by going with the 4", not enough a skunk will notice :p . Accuracy should be real close if you do your part.

i would get the 6 inch barrel but i like a long barrel on a gun

The extra 2" will reduce the recoil and noise. So unless you expect to have to fast draw the 6" barrel is a better choice IMO.

6" is more accurite but harder to pull & carry plus added weight

I've had the 4", the half lug 6" as well as the full lug 6" and liked them all. I prefer the 4" for portability and there's not that much difference in accuracy unless you're taking really, really long shots.

I have the Ruger GP100 6" full lug stainless. I use a crossdraw holster in the woods. I like it a lot. Built to last.

My extra two inches has been a big advantage for me.

You need to stay on point to the OP 1" + 2" (post operation) is still less than the OP was asking about:)