The backlash in Mach works well, on my router I have set it to compensate backlash in the y screw and the x rack but playing around with ,05mm in timber is just stupidly, so I just keep it off, unless I'm doing picture imaging on timber and then its on. What you will notice it makes the machine jerk and bump as it compensates but you can smooth that out with shuttle speed if I remember correctly.
Yep for the price of things might as well put ball screws in, and be done with it, then I've still got all the original screws untouched if ever I plan to sell the machine.
Thanks Everyone.