Michael, I’ll try but I don’t have an engineering background, well not this sort of engineering anyway.
The saddle is very short so even with the gibs adjusted as tight as possible while allowing movement there is still detectable play – think rotary looking vertically down on the saddle.
There is simple backlash adjustment for the leadscrew but it soon reappears, likewise for the saddle traverse, mind you backlash can be allowed for by working methods – I have learnt something at least.
It doesn’t compare in any way with the Cowells for “feel” – I can’t put it any better than that.
For the size of component you are working on the Proxxon may be a better bet – but I have never seen one.
Variable speed is great though
It strikes me you are down to watchmakers sizes so maybe consider that category of machine – price a big issue again I suspect.
Hope my ramblings help a little.
Andy