@Martinjmpr - my use case is very similar to yours (4500 lbs camper that I tow behind a midsize)
I currently use a GM Canyon (Exact same as Colorado) and it's been great - it's a phenomenally good little adventure truck in terms of it's off-road ability and comfort, and I think it's fantastic on the highways and in cities. The NA V6 is very peppy, and it's turning circle and overall size make it a joy to drive in virtually any city or town. I've posted elsewhere that I joke that it is a "Sports Truck" because it's such a fun driving experience compared to my last full size which was decidedly "truck like", but I still don't hesitate to really thrash this thing off road from time to time and it takes it all and comes back for more.
Mine tows pretty good in terms of how it handles; I've towed 7000 lbs a couple of times, but primarily tow a 4500 lbs single axle camper. It's worth noting that the truck is built out for Overlanding basically at all times for the past couple of years - meaning I'm running close to my GVM just in truck form, and when I add the trailer I'm likely one of the heavier mid size truck-and-tow combinations on the road.
The truck is lightweight even at max - 6,000 lbs -- so my opinion is that a good quality trailer makes a huge difference on the tow experience. Mine is
not a good quality trailer; it's a single axle on leaf springs so it bounces down the road like a damn kangaroo, and it's actually quite big and has got quite a big cross section that catches lots of wind, which I will say overall makes the towing experience not as good as it could be even with my weight distributing hitch. But I will reiterate - that's my particular trailer. As soon as I have the funds, I will likely be swapping the trailer to one with better suspension - the heavier trailers I have towed with better suspension tow like a dream. However, I mention this as you too may be blessed with a trailer of questionable quality, and if you're not in a position to upgrade that, it might be a consideration for you.
The only other caveat here - the V6 gasser has to rev pretty high to tow up hills; it can do so with confidence and is great at maintaining speed uphill, but in doing so it REALLY drinks the gas. I live in the PNW so every trip is up and over mountains, for me those published mileage figures are comically untrue -- as in, I'll regularly see 20-30 Liters/100 km when towing my trailer (8 - 11 MPG) in my region, which means I'm using about half a tank of gas in an hour of driving, meaning I'm stopping for fuel every 90 - 100 minutes, which is a lot. Without my trailer, I tend to get about 14 L/100 around the city and regularly can get under 12 L/100 on the highways (keep in mind I have ruined the aerodynamics with my bull bar and roof tent which adds to this) so this extra consumption when towing is significant. I bought the gasser because I had a desire to travel internationally with it, but if I were to do it again the ONLY thing I would change knowing I would be towing with it is to spring for the Baby Duramax; I've been told that the MPG doesn't really change at all for the Diesel when towing as compared to the gasser.
I do not know if the current gen of Twins have the Duramax available but there would be some used ones if you are interested.
Hope that helps and happy to answer any questions you have.