If you can test out the 28-300, even just say 40 or 50 shots outside of a camera shop, you'd probably be able to tell if it was "for you" or not. The superzoom is convenient...it is ONE lens, with huge range, and it can be deployed very quickly, with no fumbling, no swapping, no bagging of one lens and so on...it's SEE and SHOOT! Which was what Herbert Keppler was most enthusiastic about with the Tamron 28-200, which was a lens the Tamron company basically invented, and then went about revising, repeatedly, over about a decade, and then, they began expanding the top end longer.
And YES, I had the 28-270mm, which is now like an eight year-old design, maybe even older; perhaps the 28-300 is improved--I expect it actually might be. The camera a lens is used on can also play some part too...a person really needs to test stuff out, see how it works, see what limits are. "Most" zooms do get softer on the longer end, even the very expensive lenses often show a marked drop-off; the new Tamron 150-600 drops off from 500 to 600mm--and YET, it STILL shoots pictures at 600mm, and people really like it because it offers convenience, and length, at a good price! Is the zoom as good as the Canon 500mm f/4 L-IS USM? Hell no...and yet...people are buying it like crazy.
I totally "get" the reason for the superzoom. Nikon even makes a pretty expensive model. Canon has made a couple L-series models in the past, like 35-300 and 35-350-L series, white barrel monsters, as I recall.
