Any one with experience with this budget zoom Sigma 100-300 f4 DG EX HSM?

I am looking to add a 300mm range lens and came across a few copies of this lens going for around 500USD. It appears to be a very old, but I can't seem to find many reviews on it. I am mostly interested in the focusing speed, accuracy and sharpness around the 200-300mm range at f4. According to the photozone.de reports the sharpness is acceptable. What about the focusing speed and accuracy? Anyone have on the field experience they can share? How is subject tracking indoor and outdoor?

It was not a "budget" zoom at all, and it was one of the many amazing ground breaking long zoom lenses SIGMA introduced in the early part of the century.
(it's around 2004 release if I recall correctly)

The EX HSM = SIGMA's top lenses, both high end build quality (EX is sort of equivalent to "L") and HSM, where SIGMA was the first 3rd party lens manufacturer to crack the slow noisy AF barrier.

This lens was released about the exact same time as the still very popular 120-300mm f/2.8 (now on it's 4th version with the "Sport")

At the time these two lenses were by far the best xx-300mm zoom lenses made by ANYONE.

It will allow AF with a 1.4x t-con on any camera.

Compared to todays zooms I am sure it is long in the tooth, and it's never really became very popular, overshadowed by it's larger faster big brother. I had a play with one many years ago, and loved it. The copy I shot with was very sharp, a lot like my EF 70-200mm f/2.8L IS gen 1.

Here's a few write ups;
http://www.fredmiranda​.com …rpage/16/cat/37​#poststart
http://www.imaging-resource.com …-f4-ex-dg-hsm-apo/review/

A friend of mine had one... I played with it very often, and one night, while he and I were out playing in the dark, he started the switching lens process, and laid it on its side on the hood of his truck. It immediately rolled, and in an attempt to prevent it form hitting the hard parking lot surface, he dropped the 16-36 he was mounting. He also failed to prevent the Sigma from hitting the ground....

I was at the other end of the truck... I hard the first crash, and then a 2nd, and then a lot of swear words.... the Canon was still usable, but very stiff... the Sigma hit on the mount, and cracked the glass at that end.... the repair estimate made this not worth it