I think how big the tires look on the truck does depend a lot on A/T vs. M/T, brand, wheel width, how many miles, etc.. I think the 255s fit the look of the 4runner and the Tacoma really nice IMO.
The 305/70/16s were too wide to tuck up inside my rear fenders w/ SR5 flares and stock wheels. The body would sit on the edge of the tire and act like a brake when I would try to stuff them. You'd have to cut maybe .5" or so off that inside lip of the rear fender (which is what you need to do with 35s too). The 305s also rubbed bad in the front on the firewall when I would turn. I hammered the pinch weld and firewall area a lot more than most people w/ 255s or 285s and they still rubbed pretty bad off road even after that. All that annoying rubbing wasn't worth the extra 1" or so width.
In hindsight, I'm glad I did all that hammering because now the only place I can make my truck rub w/ 255s is on the plastic fuel filler hose cover in the inside of the driver's rear fender. But I can only hit that because I have a lot of travel back there.