Summary: Much more useful than the 18-55mm kit lens. I do have to disagree with some other reviewers about where this lens is least sharp. From my images I find that a small range at about 22mm is worst for loss of edge sharpness. I find that at 135mm, where some other reviews say it's worst, I have no problems whatsoever, even using Clear Image Zoom (2X enhanced digital).
Summary: I bought this to replace the 18-55 kit lens on my Sony A57. I get sharper, and brighter images from 30mm on up to 135. I also noticed at 18mm, the photos take on an almost 3d look to them, the sky looks great with good depth. It has a very useful zoom range for a walk around lens, plus, you can combine it with Sonys excellent in camera 2.0x zoom, and double the lens reach from 135mm to 270! I highly recommend it over the Sony 18-55 kit lens for great pics!
Summary: I bought one of this lens for my brother for his new a65 and after trying it out, I decided to get one for myself. It is very quite (relatively) in autofocus and I love that I can do direct manual focus without moving any switch. I haven't done any extensive test on it but from what I can see with my naked eyes, it is far better than the 16-105mm I had before.
Summary: I replaced my 35-90mm lens that seemed to have stripped gears. When I first tried this new lens I thought it was not working since I did not hear it working. When I looked through the viewfinder I saw it was working and it seems to focus quicker and very quiet. Works great and telephoto range covers any thing other than when needing a major telephoto lens.
Summary: If you are upgrading from a kit lens or looking for a lens better suited to the wide array of shots traveling can present, this is an excellent choice. The lens is built solid, has a nice weight to it, and zooms smoothly. Great value for the price.
Summary: I got the Sony 18-135mm lens for $300 as a 'kit' lens with the Sony SLT-A65 camera (the kit lens costs $300 extra). The Sony 18-135mm lens is almost exactly the same size and weight as the Sony 18-200mm lens which came with my Sony A700 camera, which gives a wider range up to 200mm, so why bother getting it?
Summary: I bought this for my a57 instead of the kit lens and I REALLY like it. Nice range of focal length, decent (not great, but decent) speed, focuses quickly and accurately, images are sharp, nice bokeh at the wide apertures. When I'm traveling light, this is the only lens I carry.