I bought a 2013 Durango w/ the 5.7 V8, AWD. Its the R/T model. My trailer is about 4100 lbs dry so maybe a bit over 5000 loaded up. I just took it out on its maiden voyage after breaking in the engine for about 1500 miles. It pulled the trailer easily most of the time, I went up a lot of mountain roads and it did well on all but the steepest of the inclines where is stayed in a lower gear and topped out about 50mph. Other than those couple of hills it pulled up the others fine.
What I am regretting now though is for us we prefer to boondock and the Durango does not have running boards or any sort of mud flaps so I got a lot of small scratches on my lower rocker panels, I am sure a lot would have been avoided had I slowed under 25mph on the dirt/gravel roads but I now wonder if say a Tahoe or Armada may have been a better choice as they sit a tad higher and have the option of mud flaps and running boards. Of course the Durango R/T has a more aggressive stance than other Durangos or SUV's in general but for us its a great vehicle for what we need it for the other 98% of the time so I decided to compromise and just slow down on those type of roads instead of getting something else.
I would not mind a truck but my wife is convinced she likes the smaller feel of driving the new Durango and we NEED a SUV and not a pickup. I love the vehicle, i just cringe thinking about gravel/dirt roads now.