The M1901 sight has the potential for more precise and repeatable elevation adjustment, if you have a suitable sight micrometer.  The aperture is way too small for most us; if you are target shooting, remember that you need to be able to see and read your target number as well as focus on the front sight.  The sight was made with two different sizes of aperture:  too small, and way, way, WAY too small. If the light is dim, you're scrod.  Already talked about the ad hoc windage adjustment.

The swing-up aperture on the M1902 sight is also way too small, at least for me.  I used to leave it down;  on my "shooter" sight, I just removed it and put it in a safe place.  The notch is also way too small, or too "fine" for me, even when I was 18 years old.  The notch on my shooter sight was opened up so there is plenty of white on each side of the front post.  That was 45 years ago; if you do that today, someone would probably lynch you.

If you are only going to shoot 200 yards on those huge targets (SR) used in the CMP matches, then the ad hoc windage adjustment of the M1901 sight is not a show-stopper.  You'll probably just get centered up and not have make any changes through the match.

If you plan on shooting more precision matches at 300-600 yards, you will probably have to make several windage changes in the course of a 20-shot match, unless you can determine the average conditions and sucessfully wait out the changes ... and your windage adjustments with 30-40 velocities will be way bigger than with .308, 30-06 or whatever else you may be used to shoot mid-range with.  In that case, the screw adjustable windage of the 1902 sight is a decisive advantage.  The less than precise elevation adjustments can be dealt with ... there is seldom any reason to change elevation setting once you know your zero, and most shooters can hold off for elevation much better than for wind. 

That's my story, and I'm stickin' to it.  ;)

Resp'y,
Bob S.