First time I installed it, I did configure with matrox software and so on. Months later, I formatted my system and made a clean installation. This time I did not installed any Matrox software and th2go works just fine, windows simply see the th2go as a big plug´n play monitor, not as a weird device with drivers needed.
I suppose I would have only to plug the second th2go, let windows see it as another plug´n play big monitor, and then configure screen spanning in control panel.
I don´t understand what do you mean when you talk about 2 usb devices. 2xth2go would be similar to have an extra monitor in the 2nd output. No drivers needed.
In fact, a couple weeks ago I had a fourth 7' touchscreen monitor attached to my second output. Only needed drivers to be able to use touchscreen (through usb), and did word just fine (even I installed a pivot software utility to use with the touchscreen).
My concerns are more on the side of the extreme resolution that is possible.
Software tends to not like 'more than one' like for example, nvdia's custom res. dialogs only save to the first of my 3 monitors, no matter what I do. That's because when I test a new res. before being allowed to save it, it resets to first monitor being selected.
I´m not planning to use any custom res, so I dont see any problem here.