I converted my Sieg 2.7 to CNC and I am happy with it.

What can I say, it's Chinese, so you will need to adjust and improve a couple of things here and there, but nothing major, or difficult. I had to grind a bit of the underside of the table to be able to fit the ballscrew, but other than that it was a straight forward conversion. I read this forum extensively to get me acquainted with what drives to get, steppers, etc. and eventually I made my own toroidal PSU as per instructions in this helpful forum.

Don't expect super fast speeds or large widths of cut, it's a small mill after all, but if you are sensible, you can have a nice machine that you will enjoy.
The main negative is that the head is fixed, i'e, it doen't swivel or tilt forward or backward, so for tramming you need to shim the base of the column which requires a little more patience, but quite doable. If you were to get this mill, get the version with the longer table.