Lens advise please
It is difficult to tell whether this will be addition to your lens line-up without knowing what's in your line-up. My opinion is that it is so much more suitable for an APS-C camera than the 28-105mm you mentioned. If you only have a 18-55mm and want more range than you could consider this lens, but compared to the 16-80mm, 16-50mm it falls short.
Here is a review: http://kurtmunger.com/sony_dt_18_135mm_f_3_5_5_6_id329.html which might help with your decision.-- hide signature --
Yes it is this review that got me thinking. I currently shoot with the KM 28-105RS most of the time as I like its flare control but when I want a little more versatility on the zoom I use the KM28-135 hand shake. I also use the beercan or a 75-300D if needed. My sony 16-55 sits in the bag waiting for when I need a wider lens but this seldom happens as I know with the difference in IQ between the sony and my minoltas I usually put up with the 28mm length. This is why I was thinking of getting a 16-105 when the sony 18-135 came allong. More thinking I am a procrastinator if you ask my wife