I am an amateur photographer in the process of buying a Canon 30D and had originally packaged it with the Canon EF 24-70mm f/2.8L USM Autofocus Lens and the Canon EF 70-200mm f/2.8L IS USM Autofocus Lens packaged with all the trimmings. After talking to the sales agent for some time, however, he pushed me towards the *NEW* Sigma 24-135mm f/2.8-4.5 Aspherical IF SLD Autofocus Lens. I can find product reviews for older models of Sigma lenses with the same specs and quite frankly they didn't rate well, although, considering the price that this lens is put at I feel that it must be significantly better? The original Sigma 24-135mm f/2.8-4.5 Lens goes for just a few hundred while this *New* version is apparently worth $1,399 according to their site.

http://www.expresscameras.com/prodet...d=8916&start=1

Basically, what I would like to know is if anyone has used this newer version of this Sigma lens and if they feel that it lives up to the hype that the sales guy was putting forth, or if I should revert back to my original feelings and get the Canon EF 24-70mm f/2.8L USM Autofocus Lens or perhaps the Canon EF 24-105mm f/4L IS USM Autofocus Lens, even though either of these cost less according to the same site?

One other thing, you might want to know the way I intend to use this equiptment before you go recommending lenses for me. I spend a lot of time in Kenya and intend to eventually settle there permanently. I would be using this camera and lens mostly in a walk around style, or from trucks if on safari. I also participate in a lot of ecological projects there and do foot based exploration of the bush as well. It can be dusty there, which is why I was insisting on L's in the first place, so I need to know that the build quality of the lenses are good, and not just the optical quality. So I need to be sure that even if the optics of this Sigma are superb... can it survive when subjected to my potential conditions? Not that I'll intentionally abuse my lenses of course, but I have to think about all the posibilities.

Thanks in advance,

Erick