Oh, and Voivod were never really math metal. In the early days they were very thrash, then they added some progressive elements and slowed down to play a little more proficiently. After that they started to play more of a loose rock, less technical and more rhythmic. Then everyone started leaving and the last I heard they were very simple and going for a more "aggressive" approach. Hopefully with Snake's return the band will leave that time period behind.
Some decent "math" metal bands would be Candiru (warning, tastefully well performed hip hop elements as well as freeform jazz), Maudlin of the Well, and Lamb of God.