So here my first day impressions. 

First of all, this lens is an extreme bargain.  Mine, bought from Cameta Camera on eBay, cost only $119.95 plus 9.00 shipping, plus less than $10 for a cheap UV filter from S+W.  The lens comes with its own lens hood, unlike for instance the Canon 28-135mm IS ($400+ but no hood). 

As many folks reported, the AF motor is loud, and it's also slow, especially if one is used to Canon's USM ring motors.  The difference is quite substantial, and makes really fast "action photos" with AF pretty much impossible.  Further, with a largest aperture of 4.0 (5.6 at extreme tele) this is not a high speed lens, but still very reasonable. 

The lens is astonishingly light, slightly less than one lb., due to the fact that much of its casing is made of plastic.  But the contact to the camera body has a metal plate.  A touch of quality. 

And the picture quality?  ... I like it!

Very reasonable sharpness, nice colors, and nice bokeh!  The flower shot below ( although a little underexposed) is quite nice.  The same is true for the leaves and the car shot (the latter one's both 1:1 shots--not size reduced, just cropped). I did not apply any sharpen or contrast filters.  What you see is what I shot.

Overall I think this lens will be quite satisfying for taking non-extreme tele-shots if the light's right.  Mounted on the EOS 10D, this lens has a maximum effective focal length of 480mm and thus needs short exposure times, at 5.6 or smaller aperture.