I have a DualHead2Go Digital sitting in a box somewhere. My work obtained it for me several years ago (just when the Digital was released) so I could use 2 22" monitors w/ a 2006 vintage MBP. Good thing was that it worked. Bad thing was it didn't work well enough to actually be useful. Since I'm Unix geek and spend almost all my time in a Terminal or something close to that; the 'crispness' of text output was of paramount importance. The Matrox totally failed on that account. It was fuzzy and jittery and unusable for 8+ hours a day.
As I recall, I tried different cables, resolutions and other stuff but could never get it to fulfill its promise so into the cardboard box of disappointing technology it went. That was before I got back into digital photography so I have no info on suitability in that domain.
Your mileage may vary.