Excerpt: Sigma's 105mm macro optic costs around £380, which is the same price as their more recently released 70mm F/2.8. The 105mm gives a little comfortable working distance, which should make it easier to light your subjects at high magnification, and you are less likely to scare off the subject. It is also more flattering for portraits.
Pros: Good build quality, Easy to switch between manual and auto focus, Smooth manual focus action, Recessed front element reduces need to use supplied hood
Cons: Lacklustre performance at maximum aperture, Slow, noisy AF