good backup lens

i shoot with d200's and have XD 18-70mm lens on one and a 18-200 VR on the other-I use D70S for backups and have 2, one with a Nikon 55-200 XD and the other has this 28-200 mm Tamron XR-this lens gets a decent amount of work, and is small for what it can do-I have not had any problems with sharpness, but make it a habit to try to shoot in well lit areas when going past 120 mm or use a tripod-it will not handle shake like the Nikon VR lens, but it also cost about 1/6 the price. Higher ISO (within reason) and faster shutter speed goes a long way, and I can grab it and get a good shot without removing lenses and risking dirt in the camera body.