Right given the lack of negative comments on the last revision of my design, i'm starting to move on to the next stage which brings me onto another set of questions...

Gear ratios & microstepping.

After reading around, it seems that the general consensus is that less microsteps are better ie, either use full steps or at most, half steps.
My understanding is that the accuracy of the stepper motor gets lower when the number of microsteps is increased...I think this also has an effect on the torque?

Couple this with the gear ratio from the stepper to the leadscrew makes the choices a little open ended as far as I can tell.
The general flat answer for the ratio that I seem to see is to use 2:1.

I'm only thinking about the X & Y axis at the moment which are both going to use 1610 screws. Belts/pulleys will be 5mm HTD 15mm wide.
Full step geared 2:1 gives a resolution of 0.1mm
Half step geared 2:1 gives 0.05mm
Full step geared 1:1 also gives 0.05mm

0.1mm sounds quite a coarse resolution to me - 0.05mm sounds more like it. So why gear 2:1 & use half step when the same resolution can be had with full steps & 1:1?

or perhaps go for a somewhere inbetween like 1.4:1 (eg 28/20) full stepped = 0.07mm ??

Am I missing something here?