I got my sx3 down to .0007. I'm not sure if it will stay. It took a lot of careful tweaking.
As described in Kreutz's thread, I measure backlash, with a dial indicator. I move the table forward until it pushes the indicator, back off slightly and then zero Mach and the dial indicator. Now I move the table .1" to make the dial turn exactly 1 revolution. The deviation from zero is the backlash.