There is a **HUGE** difference between the MX400 and the MX200. The 200 is a lobotomized card. The only thing Geforce about it is the name. This card was only made so that PC venders could say "Geforce2 card included!" and for people who dont know any better to buy. Its quite sad really.
It performs more like a TNT2 then a Geforce2 card. Honestly! I have seen benchmarks comparing the TNT2 to a MX200! I researched everything I could about these Geforce2 cards for a month before making my purchase. And im glad i did.. I might have bought a mx200 buy mistake :-(.
Here I found this old link I had. Take a look for more information about the differences between the mx400 and mx200.
http://www.planetsavage.net/hardware/siluro/index.shtml