I've been operating with a D5100 and two lenses; an 18-55mm (kit lens) and a 55-300mm telephoto. My son bought the new D5100 and the 55-300mm from me. I ordered both the D5100 and the new 18-300mm lens to keep from having to switch them out. We just returned from an Alaskan cruise and I used the telephoto lens the whole times because the issue of the carrying two lenses - hard to do on excursions. I kept the 18-55mm lens as I do a lot of stepped focus macro photography for my modeling business.
Anyway, have you any experience with this new lens? Any issues to report other than weight?