Vic,
I bought my mill/drill in 1974 as scrap from Jet Machinery. It had been dropped off a loading dock and was pretty badly broken up. A friend of mine who is a WELDER (that's capital letters and no smile) welded up the broken castings for me and I put it back together. The first thing I found was that the column was out of alignment to the table to the tune of (about) .015 in/foot. I remachined the socket and brought that back to true. I then found out that the Y-axis was out of true to the X-axis by about .010 in/foot. After rework, I brought that back to true.
I had assumed that these conditions were the result of the drop. It has turned out over the years that most mill/drill units suffer similar problems. [I have helped mill/drill owners "true up" eight of these units in the intervening years.] My experience, limited though it may be, is that Rhong Fu machines are slightly better than the general Korean/Chinese/Indian units -- but that rework is in order on every one of them that has passed through my hands.
Back in the mid-90's, a friend of mine bought the "top of the line" Rhong Fu mill/drill. The column was out of true by .027 in/foot and the Y-axis was out of true to the X-axis by .017 in/foot. [How anyone let's something like this leave their factory is a complete amazement to me!] He tried returning it for replacement (twice), but both of the "replacements" were similarly out of true (probably all from the same "lot"). 20 hours of work later, he could flycut a face and leave both "trace lines" in the finished (light) cut and square a piece within .001 inches in 6 inches of length.
I find this to be quite typical.
