Sorry for not explaining my other lens, it`s a Canon 24-85 ultrasonic, I think it is an older model.
I believe the 24-85 USM was introduced in 1996. I've just picked one up second hand to use as a lightweight travel lens for FF, and in first tests it seems pretty decent. It's got fairly strong barrel distortion at one end and pincushion at the other, but I don't do much in the way of architectural shooting - and when necessary, it can be corrected in software. Sharpness and contrast seem fine, if not up to my 24-105L - but it's a lot smaller and lighter, and cheaper.