I have the Tamron 90mm 2.8. I bought it mostly for shooting on my 5d mkii, but it now lives on my Elan IIe in the passenger seat of my car. The autofocus feels a little janky compared to my USM lenses, but I find the manual focus far easier to use than the canon flavor. In all, I think it is probably one of the best values for sharpness in any modern EF mount.