Got multiple quad cards, waiting in the wings. Used matrox quad cards are cheaper than 2 new dual.
If 1 dual card goes out, just put in the quad card. Beats being dropped down to 2 monitors.
Another great set-up, idea: If you MUST have some 128+mb cards....like gnome said go real deal ATI duals.Get a cheap matrox quad to put away for back-up, if one of the duals goes out. It's a great cheap back-up, and allows you time to get another replacement dual.