This lens is a far more worthwhile investment than the small, cheap zoom lenses that come bundled with most DSLRs. The focal lengths cover almost everything that an entry to mid-level photographer could need, from wide angle 18mm to capture landscapes to the telephoto 200m to minimise the depth of field for engaging portrait shots.
It is a robust lens which feels sturdy and well built compared to the evidently cheap build of, say, the 18-55mm zoom lens which came with my Canon 400D camera.
Its main drawback however is that is not a particularly fast lens when you have it on maximum zoom, with the widest aperture at 200mm being just f6.3, which means that the shutter speed has to be quite slow to compensate. This is inevitable however, unless you are willing to fork out a substantial amount of money for a much pricier lens.
This lens produced some stunning results on a recent safari trip, and it coped well with a range of focusing distances as well as the environment.
If you have invested in a DSLR camera, then it would definitely be worthwhile to add this to your kit - unless you are thinking of becoming a professional photographer, this lens should cover most of your requirements.