Everybody needs a telezoom!
As I said, the first lens I bought after getting my first SLR (the good ole Dynax 404si). The kit lens covered 28-105 mm, 24mm was not yet widely available, so what do you do? Buy a telezoom. On a second-year PhD-salary, you buy second hand. So that was this one.
Of all lenses, this one is obviously the one that benefited most from my upgrade to the α700. Firstly, there’s the 1.5-fold ‘crop factor’ that comes with the smaller size of the chip compared to 35mm-format – the bottom reach of 70mm was never that important, with my most-used standard zoom lenses getting to 105mm and 135mm – the aft-mentioned Tamron 24-135mm, it was all about the far end. Secondly, image stabilisation in broad daylight is nowhere more important than on telelenses – and the alphas of course all have in-body stabilisation. So basically by getting the alpha, I also got, for free, a 105-450mm image stabilised telezoom lens. Not bad, methinks.
What’s it like, then?
Initially I rated this as “really good” but I’ve become (quite a bit) more critical about it recently. I keep struggling to get proper focusing when shooting stars – even when the finicky focus is on target (the focus ring turns way past infinity), the focus ring is so loose, it will just lose focus like that.
Example:

Ugly! Out of focus!

Ouch :(