I have a mini lathe, and the basic machine is pretty good (excellent for that price).
My head stock aligns down the bed very well.
The saddle dovetail cuts a slight concave, as expected.
The tailstock is truly aweful.
Here were a couple of the checks I did...
http://www.wrathall.com/Interests/ma...ent_check1.htm
If you treat the machine as a lathe kitset, poorly assembled for shipping, and are willing to invest the time into deburring, modifying, and adjusting, the machine accuracy will be a reflection of your accuracy/workmanship.