I have tried this lens for a long time ago.
The lens is perfect for shooting portraits and close-up shoots 500mm - 2m range.
The worst thing i have experience using this lens was, when u dropped it, surely AF will be not working anymore.
And another weird thing happen was when i used it with my canon 40D which i have set my camera aperture to f22 *heared the sound like exploded internally near the shutter button resulting to damage my 40d. The lens working perfectly Which i have try to test with other camera. From now on, i never used this lens with aperture f15 and above. Usually i used kit lens to check my camera sensor from dust which can go higher to f30.