Here's the "official" ratings straight from Dodge.com/towing:
With 3.55 Axle Ratio Axle Ratio [i] You Can Tow 6300 lbs

Gross Vehicle Weight Rating (GVWR)
[i] =
6700 lbs

Payload
[i] =
1662 lbs

Curb Weight
[i] =
5038 lbs

Curb Weight Front/Rear =
2847 lbs/2847 lbs

GAWR Front/Rear
[i] =
3700 lbs/3900 lbs

Gross Combination Weight Rating (GCWR)
[i] =
11500 lbs
With 3.92 Axle Ratio Axle Ratio [i] You Can Tow 7300 lbs 
Gross Vehicle Weight Rating (GVWR)
[i] =
6700 lbs

Payload
[i] =
1662 lbs

Curb Weight
[i] =
5038 lbs

Curb Weight Front/Rear =
2847 lbs/2847 lbs

GAWR Front/Rear
[i] =
3700 lbs/3900 lbs

Gross Combination Weight Rating (GCWR)
[i] =
12500 lbs
Now, for some personal experience. I have as you can see by my profile a 2005 Safari. Up to a few weeks ago I was pulling it for almost two years with a 2005 Dodge Dakota SLT Quad with 4.7L V8. Oh by the way, it wasn't stock either, as the stock engine was not strong enough despite what the ASdodge Dealer might tell you. I had a cat-back system, computer chip, 180 degree thermostat and the tow package. and my towing capabilities were 7000#.
We never filled up the potable water tank or went anywhere with the trailer filled up. Couldn't even load to full capacity the bed of the truck as the truck constantly ran hot. Couldn't use the A/C which was "hell" trying to go through the desert or hills. Went to Lake Tahoe and Yosemite last year and blew the exhaust manifold and had to have a few bolts extracted from the block. Thank goodness the truck was under warranty.
So, to make a long story short, I now have a 2007 Dodge 6.7L Diesel with Automatic trans. Yea it's overkill but, I can go anywhere WITH the A/C on, the bed fully loaded and then some! Oh, I get better mileage then I was getting on the Dakota too! Oh, and the 6.7 puts out 50% less noise then the 5.9 or other brands.
As for the "Hemi" it's great too, but the gas mileage sucks! both w/wo towing.
Anyway, that's my 2 cents worth.