My favorite floorplan in the world! We looked at one back in '06 and fell in love with it, but...we were really after a hybrid and at that time didn't want to spend the extra money. And it was heavier than DH wanted to tow. This past year we made the change from our beloved HTT to a TT and looked again and still loved it, but it still weighed more than we wanted. We bought the one in our sig and love it, but that 264 still lurks in the back of our minds. DH was impressed with the build and we both loved the fit and finish. While there aren't a ton on Surveyors on here, the ones who have them seem very satisfied. Don't think you'd be making a mistake.
Is that 6000# number GVWR or dry weight....as I recall, the Gross was over 7000#. Our max capacity is 8000# and we're at 6629# with Rocky. Looking at a weight sticker on one online, the GVWR is 7800+. Too much for our F-150.
Re mileage...most feel like it's a good day if you average 10 mpg. Larger or smaller doesn't make a lot of difference, it's that big ole front you're dragging down the road. Happy Camping!