I have been a strong proponent of Ronchi testing over the years and have gotten a lot of flack for it. So, I am glad to see that others have found it useful too.
Perhaps a distinction between testing a finished scope and testing to figure a mirror could be made. I certainly agree that solely using the star test to figure can be exasperating since it is difficult to nail down zones. And I too have found that figuring my mirrors to make the Ronchi bands look exactly perfect, then star testing the mirror has always revealed an excellent result. Nonetheless, for the average amateur, I think that periodic star testing while figuring using Ronchi (or Foucault or Caustic or whatever) is very useful and instructive.
John Dobson figures his mirrors solely by star test. His mirrors are awfully good, too. I suppose it is whatever you get used to. On the otherhand, there have been numerous times during my figuring that when using several different tests revealed something about the figure that indeed was present in each test method, but difficult to see initially.
Mel Bartels