.Thank you for your nitpicky contributions that do nothing to usefully aid the OP
Your welcome. I am always glad to clear up misinformation that you provide.
1) 1:1 is neither a universal definition by any means of "macro," nor would it really matter if it were, since one's enjoyment of photographing small things does not magically begin at 1:1, and I was very clear and accurate (and actually attempting to be helpful...) in what I meant to say, even going so far as to include an example.
Must be an Iowa thing, cause the rest of the world is on board.
2) I was referring to the MP-E 65mm f/2.8 1-5x, which I suppose is their 2nd most expensive macro lens. I'm sure you knew this full well, and the point still stands that many people will focus entirely by rocking back and forth/using rails, not by using a focus ring or AF or even MF. Especially if using focus stacking, which is virtually impossible with AF.
So your point still stands that the lens your were talking about, the MP-E 65 doesn't have a focus ring? Funny, I OWN that lens and it DOES have a focus ring that IS used for micro focusing. If you ever owned and used the MP-E 65 you would understand that it is not your typical macro/micro lens and as such is not used in the same fashion. That is why when I'm doing general Macro work I use either my 100mm f2.8 macro or the 180 f3.5 for the working distance and DOF that they provide over the MP-E 65.
The MP-E 65 is an excellent choice for static Macro/Micro use. It is not the best choice for a general macro field use.