1500 or 2500 Silverado

If I were you, I'd keep the truck you have. If you're happy with it and using it within its limits, you're not going to break anything and there is not reason to upgrade. Keep up on maintenance and you'll be fine. On the other hand, when the time comes you really need to replace it, or want to, I'd get the 2500. They do handle the trailer better and you have less to worry about from a payload perspective. It will also allow you to upgrade in trailer size later if you want. The other good thing about the newer HD trucks is that they get fuel economy that compares to 1/2 tons from 10-15 years ago. The newer 6-speeds in the 2500's get much better fuel economy compared to when they used 4-speeds. They aren't really any bigger other than they sit up higher. Same bodies for the most part. The frame, suspension, transmission, etc. are all beefier and weigh more which is why they use more gas and handle the trailer better.