Does anybody who has used either (or both!) of these lenses have any opinions of them? I've found a little on the Tokina, but the Tamron I've had a lot of trouble finding really anything about, other than specifications. For the Tamron, I'm looking at the manual focus adaptall f/5.6 SP version, not the newer AF version nor the f/6.9 adaptall version. All I can tell so far is that the Tokina is slightly smaller than the Tamron, but I haven't seen any tests or significant opinions on the image quality of either lens. Picture samples would be really helpful, as well as comparisons that anyone has done to modern lenses.