I don't want to make things more difficult, but the Tamron 90mm macro always gets good reviews. The IQ is good, and in the comparisons I have read, it beats Sigma, but as is the case with most Tamron lenses, the autofocus is rather slow. So if you are hunting bugs, I guess it is out of the question. Also, no IS. But it considered a good buy, due to its low price and high IQ.

Lars