Well, I managed to do a road trip up into Oklahoma this weekend and did not have my 28-300mm. To cover the range I had a 16-35mm F4, 80-200mm F 2.8 and a 50mm F1.4. Well, I learned to NEVER do a road trip without my 28-300mm again. I really didn't appreciate the versatility and picture quality of that lens until I spent a full weekend without it.
It seemed like I was constantly swapping lenses in the car where I usually never have to trade lenss. Then during one of the lens swaps I got a big piece of dust on the sensor that will require some PS to remove from the pics. I missed shots, got poorly composed shots, got dust bunnies, got frusterated a few times. When I got the pics home, the colors in some skies were off (especially those shot with the 80-200mm ED IF F2.8 lens).
After this weekend I think I'll ebay the 80-200mm, it does absolutely nothing that the 28-300mm doesn't do better. I'm convinced more than ever that the 28-300mm is the best bang for the buck lens made. After this weekend, I'm convinced I could easily live with nothing but this lens and maybe a dedicated macro lens.