I read most of the stuff on the Gecko site. I am using 4 of the Gecko 203v drives.
Power is one consideration, certainly, but steppers cannot do tiny jogs accurately and I've been told on this forum that this is inherent in microstepping.
I have had problems with the steppers loosing steps. An interesting paradox of these el-cheapo asian machines (mine is the X2) is that the ways are so crappy and inaccurate that i find I have to run them fairly tight to have any chance of keeping some accuracy in the machine. Moving the tight tables, and especially the head, take more power than cutting the part.
The Y axis on this machine was a huge PIA to get working. If I set the gib for a nice sliding fit at one end of the travel, it would completely jam befor it could get toi the other end. If I set it for a sliding fit and the tight end, it would literally be clunking back and forth at the loose end.
I had a binding problem with the Y axis ball screw which turned out to also be caused by the bad machining on the X2.
You get what you pay for. I did not expect to get a fine accurate machine, and in manual use, it's actually an OK little brute. CNC really showcases the limitations though.