I did the overhead thing, but took a slightly different route. My space is 20 x 30 feet, so I have a lot more empty center floor space. And the lathe could get moved at any time if a new machine showed up. So my shop arrangement is far from being firmly defined.
I already had a 7 ft power cord on the lathe. Then I made a 220V 4-prong extension cord about 20 ft long and strung that up overhead. The thinking was I might get a mill or welder requiring 220V in the future, and I definitely can't use them at the same time. Better for me to have one really good extension cord I can move around, rather than have to keep adding expensive breakers and outlets.
But the others have it right. The trick with overhead wiring is figuring out how to keep the weight of the vertical cable from cutting into the insulation of the delivery cable where it transitions from vertical to horizontal. That 15 pound dead weight will surely get you in trouble over time.