Apart from an extra 10mm in focal length, the Tokina macro lens bears more than a passing resemblance to the 90mm Tamron.
Similarities include noisy and slow Autofocus, a non-rotating front element, the same push-pull mechanism on the focus ring, and a lens that doubles in length at its closest setting of 0.3 metres.
As for differences, the Tokina sports an aperture ring, which you can lock at f/32 with a locking switch, and the lens is available in either Canon or Nikon fit.
In our tests, the Tokina didn't capture as much fine detail as we were hoping, even when stopped down from f/5.6 to f/11. We also often had to dial in a third of a stop under-exposure to avoid blown highlights and washed-out colour.
Overall, the Tokina is a solid lens at the price, but it's not the best.