To the OP, After our PM exchange, I came looking for the discussion to give more detail.
The info on the NV is a bit confusing, I learned that first hand when we bought ours.
One of these days I want to get the whole setup to a scale and get the actual weights, but I'm comfortable with it.
Unfortunately, the SV version does not have the best equipment for towing in the upper weight ranges. The weight limits are the same on the van, but the list of standard features on the SL make towing better: standard V8, different axle ratio (a big key point, IMO), receiver hitch is rated for 1000lbs tongue weight (with weight dist, of course, and not listed in the regular owners manual). In an SV model, I think I'd try very hard to stay within the listed weights, especially if it's V6 powered.
We shopped for a TT in the 6500lb dry weight range, knowing we'd add another 1k in gear. We ended up MAYBE pushing right at 8K fully loaded / ready to camp for a week at the heaviest. We don't usually haul too heavy on household goods / personal gear as our kids are grown and someone usually drives a car from another location with more of that stuff of their own.
The tongue weight issue is a slight problem - they list 1000 on the hitch and even state that for the HD towing package, but then say 870 on the van inside the owners manual. Well which is it? I took the entire picture into account for my setup: We don't need all the seats since we never travel with more than 6 of us (usually only 3 or 4 and a dog), so I pulled out the last row of seats (and they weigh a lot). We pack some supplies and luggage in the van and a canoe on the roof, but not packed to gills - lots of stuff goes in the camper for ease of use. I'd guess even with tongue weight being about 80 pounds over (have a tongue scale and weighed it @ 950 -- but still under the hitches rating), we are way under the rated capacity of the van with about 500 lbs to spare. The suspension doesn't squat but about an inch when I hitch up, before snapping up the WD bars, and all tires have the same look to them - not overly squashed in the rear.
I believe Nissan set the ratings conservatively to account for the maximums - the people who will load 12 people in it and 1000 pounds of luggage inside and THEN hitch up a TT that's the heaviest they think they can get away with towing.
Again, My big concern for an SV model would be power train - it's gonna work harder pulling a big load without the other axle ratio and even worse if it's a V-6 engine. I'm also unsure of trans cooler equipped or not on a SV.
