Currently, Matrox doesn't support 3x1920x1200. Only 3x1680x1050. The DisplayPortTH2Go supposedly fixes that, but requires DisplayPort monitors and the TH2Go itself.
None of the issues ATi 'exhibits' with EyeFinity are anything that Matrox hasn't either suffered from in the past, or suffers from still. *shrug*
According to Matrox's website, the Th2GO DisplayPort only supports up to 3x1680x1050@60, it mentions nothing of 3x1920x1200@60. Also, the problem with that is that I would need a DisplayPort video card, which of course I don't have.
As far as I know as well (I don't have one), Th2Go has its fair share of issues, it's not bug-free. EyeFinity will probably have more issues since it's a new product, but for now, as far as I can tell, it's the only good 3x1920x1200 solution. I've tried SoftTH and didn't like the performance I got from it (also not compatible with too many games).