I have always found G2/G3 to be perfect.
If your motor tuning, acceleration and pulsing rate setup are not optimal this is the first place you will notice lack of smoothness.
If the PC speed is inadequate, or KHz speed too high, or DMA access is interrupting the CPU, smoothness of motion will deteriorate.
Read the attached, and this will give a better understanding of why it even works at all under windows.
First, get rid of ALL un-necessary background tasks, especially anti-virus stuff, automatic updates, and have at least 500MB memory.
If CPU is below 1 GHZ the attached will also give the reasons for special requirements.
If it is on a laptop, you MUST disable any battery saving setup.
Apologies if necessary to Art Fenerty, for including file. I could not find a link to it. Does anyone know the link?