I use the smoothstepper and gecko 540..
and I use it to feed a superpid to get my spindle control that's about it..
i have had it working on windows xp and windows 7 32. I think it was flaky when i tried the windows 7 64bit ..but it may of been my setup up i stuck with windows 7 32 bit..
but there were some software gotchas that applied to my stuff..
(needed a certain version of plugin for smoothstepper and a certain version of mach3)