For what it's worth, I'm very happy with my rig as listed in my signature. I also feel that my Tundra could handle another 500 lbs. or so quite easily. After that, I'm not so sure. A larger, longer trailer, althought built to be light (under 8K) is still a big sail when in crosswinds, so that can make a big difference in how a rig tows. If I had a bigger/longer trailer, I would have a Hensley hitch and use my Tundra if the weight (loaded) was 7K. But, if I went with a bigger rig, I would also be prepared to look for a 3/4 ton truck in the event things didn't work out.