While I have not towed with the V6 version, I wanted to give some input.
The new GC (wk2, 11-14) seems to be a pretty solid tow vehicle, assuming you realize it is not a full size truck. Between the sway control and leveling suspension that comes with the tow group, it provides a decent platform if you don't drive like a maniac and stay below the weight limit.
I will say the extra power of the hemi is very evident when not towing (drove them back to back), so I imagine towing with the V6 will require some patience and planning when passing. As far as gas mileage, based on what I have read on the forums (jeepgarage.com, great resource), the V6 doesn't really do much better than the V8. If you spend most of your time city driving, you will gain a decent amount, on the highway it is almost a wash.
Also, a quick pic, because threads just aren't as fun without something to look at...