One thing I've learned from using LOTS of mics and mic'ing LOTS of voices and instruments is, many times once you get to a certain level of quality, one mic is not usually universally better than the rest, as much as it's the synergy between mic and source that defines which one works the best. I have multiple mics at church and mic many singers and a full (25 piece or so on top of the keyboards, guitars, piano and percussion) orchestra. The mic that works better on one instrument or voice, is not as good on another one. The mic that works better for one singer is not best for another, etc. And even how the singer holds the mic (not an issue in a studio setup) can define which is better.
I have singers who, despite my YEARS of telling them not too, practically put the mic on their lips when they sing. One said to me a few weeks ago "that's how the singers on TV do it," and I knew the implication was that, I didn't know what I was doing or I wouldn't tell them not to do that since they saw someone on TV do it. I replied "yes, and while we have a $15K mixer, they are probably running through $15K worth of channel strip before they hit the mixer AND, it's mixed and mastered before you ever hear it on TV. I could do the same with your voice in the studio and in fact have to adjust constantly every time you sing when you do that. But it is NOT the way to make your voice sound natural and it does not allow your voice to blend well with the quartet even after I re-EQ it."
Further, one mic might be better for certain mic locations on say an acoustic guitar, and another one may be better for a different position. A mic that might be the better one might have too much bottom end if you put it in front of the sound hole in the "boomy" position, where another brighter mic may be fine there. Etc. That said, if you found one mic and "your sound" with acoustic, then spend your time USING it and recording, rather than messing with more mics and positions!