A small Chinese import lathe 9x20 or bigger.

Once you strip it down you rip out the standard leadscrews and replace them with ballscrews. But do you keep the cast iron ways, or do you bolt down linear guides such as the HIWIN type?

Is one method preffered over the other in terms of accuracy? with the standard ways it would be much easier to convert to CNC. But I wonder what accuracy difference there could be?

ie, is it worth stuffing around with extra money and time when the stock ways may do the job.