I am using the new G251X drive. These are good low priced alternative to imported drives. They are $69 each in small quantities. They are good for steppers rated at 3.5 amps/phase or less. They are not plug and play though. They require mounting, heat sinking, and optoisolation, but that's what DIY cnc hobbyists want. I was surprised that there was not a thread already started on this drive. I am already using them in a project in a thread here titled "Interfacing MO-CON501 controller/Little blue box."