My average all-up weight is ~252 lb., so pretty close. 28s work well for my daughter on her CX based bike, but her all-up weight is much less. 32s seem to be pretty good for most everything. I have some 37s on my second touring bike and from some gravel grinding on it are perhaps better for chip seal vibration dampening at the handle bars. FWIW my two touring bikes are identical frame sets.

Difficult to give a blanket statement because in my examples the rims are different widths and are Continental tires which seem to run a bit narrower than other brands.

Brad