95_stroker, the mud's caked into the tires in those pictures 'cause the ground the truck was standing on was actually still a bit muddy, and ther was a puddle not too far back. The tires actually do a good job of cleaning the mud out once I'm on dry dirt or on pavement, but they're general-purpose off-road tires (more aggressive than all-terrains, though) as opposed to mud-specific tires...but usually I'm off-roading on dry ground, so that's not a big deal for me.
Gary, I agree with you re: deserts being dry. I think this is the wettest I've ever seen the Mojave Desert...like 95_stroker said, CA's seen a deluge over the past month; even the desert got some (in fact, there was minor flooding at my dad's house).
RT, the ride didn't change noticeably, although I have yet to play with tire pressure to see where the tires are happiest at. I know that, at rated pressure, the tread's only touching pavement in the center, so I need to lower it somewhat. The steering leaves some to be desired. The shop that put the tires on also repacked the front wheel bearings and replaced the outer tie rod ends, but the steering still feels weird. Either it has to do with the tires, or they didn't align the front end properly. I'm going to have the front end re-checked by a shop in the Bay Area to make sure.
Tristan, not sure yet on the gearing. It doesn't feel noticeable, but I haven't changed the speedo drive gear, so my speedo's reading off somewhat. It probably would be noticeable with a calibrated speedo, but minor.
Mel, I was almost as shocked as you

Now if the mud had sunk into the ground instead of forming puddles... *sigh*
Animal, I think that 265's weren't available at the same height, but I'm not sure. OTOH, it's only a 1 centimeter difference in thread width, so I think the 255's will work just fine.
Ugh I forgot how much of a PITA it is to type on a laptop; my computer's down for the count...hopefully I'll have her up and going again by Monday or Tuesday...