it is decent enuf lah, like mpenza said. i've got a 2nd-hand tamron 28-200mm (bought from ah meng), and the shots are not bad. think if u really want one, have a look at buy/sell. every now and then, there are the upgraders throwing out their 28-200mm.
if u going on holiday, this lens does save u a lot of lens to bring along! i left some of my lens behind when i went to msia with this lens.