A lot of wisdom here. Should have visited before we bought. Have the new half ton for all the comfort reasons. Then started looking.
We sort of lucked out when purchasing our new TT, a 2019 Keystone 250URS. Weekend warriors right now. Full time in a year or two.
Knew I wanted something about half the dry weight of our tow capacity. Have hauled heavy stuff close to tow capacity before and it's no fun. As mentioned, so many things to consider beyond "pulling capacity". Dealer ran the numbers before we purchased but we verified with a Tow Capacity Worksheet found on a reputable site. Also purchased a Sherline tongue scale for good measure. Found out the tongue is about 100lbs more than advertised. Could be the packing but that's important info right there.
The TT is 58% of our tow (pulling) capacity. However, the tongue weight, GCVW, wheel base and other specs put us right at MY safe limits for 1/2 ton. Wheelbase is the only factor showing a bit close..
We have about 900lbs spare for the tow vehicle after factoring full tank, me, wife and dogs - per certified scales. Our TT loaded is right at 6000lbs (66% of tow capacity) and we still have another 1,500lbs for the trailer...that we'll never use. Truck is 5,120 per scales.
All that said, when it's time to hit the road for good we'll invest in a 3/4 ton. The larger truck is just not practical right now and we're willing to concede the cost of the upgrade when the time comes.