Yeah nearly all decent stepper drives are microstep which gives a smoother action but if the gearing is fixed changing the pulses per inch will cause the machine not to move an inch.
The microstep option is usually set via dip switches and not readily available and again you will need different Mach setups so my original thoughts on the law of sod still stand.
Direct drive is fine on smaller projects or on bigger ones with bigger motors but as is agreed some gearing increases the available torque at the cost of speed.
It all depends what you want to do with your envisaged machine..
How long is a piece of string?
and after all what's the point of 20metre/sec rapids on a machine with a 300mm work area? generally the smaller the widget you're making the greater need for accuracy
If you're realistic, with a hobby machine the speed isn't really the issue.
Also a point that hasn't been taken into account is lost steps. If you loose a step on direct drive it's serious, if you've a 10:1 reduction it's obviously only a 10th of the distance. Again the law of sod applies
I'm not having a go at anyone, we're all learning - whether we like it or not
and discussions like this help us to learn
(but try and prove me wrong
)
another tuppence worth