Tamron's offering is a strong performer...
This Tamron lens is – according to the US website – known affectionately as the ‘portrait macro’. Certainly 90mm is a lovely length for portraits, and even with a 1.5x magnification factor it offers a 135mm (equivalent) length with an APS-C sensor, which is still a great length for portraits.
This lens offers 1:1 magnification, and so is a true macro lens, and consists of ten elements in nine groups. As a Di lens, it is designed for optimal performance on digital sensors, but it offers a full-frame imaging circle, so is also suitable for film cameras.
The Tamron 90mm uses a dual-focus system, which has a secure click between manual and autofocus. It also uses a focus limit switch to enable faster close-range focusing. Optically it impresses, with better performance than both the Sigma 70mm and 105mm lenses in terms of sharpness, and approaching the quality of the Canon 60mm. Chromatic aberration remains consistently minor at the corners of the frame, and impressively absent in the centre.
A good choice for all-round work, with the advantage of a nice portrait focal length and good contrast.