I just got a later one in the mail, and it's got enough room (and a well designed cap iron) to set the cap iron close.
If you are getting better results with a close mouth than you get with a cap iron, something is wrong with the cap iron setup or setting.
But, you use what works.
I find the A5 to work about as well as my favorite stanley. Both with the cap iron set will (unfortunately) beat my 55 degree smoother with a mouth in the 3-4 thousandth range, though it's rare to find wood difficult enough so that the latter won't plane it well in the first place.
Not to suggest there's anything special about my favorite stanley, they are all the same when it comes to setting the cap iron. What makes it "favorite" has more to do with the proportions and its smoothness of adjustment.