I'll echo what Derek is saying. Low angle, BU planes are certainly useful and excel at what they do well. But for a true smoother, I prefer a BD plane so that I can set the chipbreaker tight to the cutting edge. Bailey adjuster or norris adjuster aren't a major consideration for me. I think they both work well, just different. All of my planes, other than my Veritas LAJ, are BD Bailey patterns.
I've done extensive experimenting with edge geometries, chipbreaker geometries, chipbreaker placement, and frog position/mouth opening. And I've come to the conclusion that ultimately the chipbreaker position with reference to the cutting edge and having a proper fit between the chipbreaker and iron with a polished edge on the front of the chipbreaker is what makes the biggest difference with respect to the function and results of a smoother. So much so in fact that now I set all my frogs so the blade bed is coplanar with the ramp in the throat and I sharpen all of my irons with a single 25 degree bevel. I just take time to make sure there is no gap between the chipbreaker edge and the back of the iron and that the chipbreaker is set tightly to the cutting edge. The other variables don't have enough effect for me to spend time tuning them.
All of the above is my opinion of course. YMMV and I'm sure there are contrary opinions out there that are no less valid than my own. These are just my conclusions based on several years of rehabbing vintage planes and comparing results to come to my own methods and setups.
Also note that all of my observations are based on vintage BD planes with vintage irons and chipbreakers. I can't speak firsthand to any modern BD planes since I don't own any. I will say that the Veritas LAJ is an exceptional plane for endgrain work and for face/edge work if the grain is straight and clear. And that plane has made me a firm believer in the PM-V11 steel. I will most likely upgrade the irons in most of my vintage planes to those irons because the edge retention is vastly superior.
Finally, on the subject of smoothers, if one works much with figured woods, a higher-pitched approach yields notably better results than a standard 45 degree BD plane. This can be accomplished with a BD plane with a 50 or 55 degree frog, or with a BU plane with a steeper bevel. The difference between the two approaches, in my estimation, is that with the higher pitched frog and a BD plane, you control the shavings (and therefore the tearout and ultimately the surface finish) with a chipbreaker. With a BU plane with a steeper bevel (30 or 35 degrees for a 50 or 55 degree attack angle) you control the shaving by adjusting the mouth opening. For me, the BD plane is a better approach. But I am positive that there are others who can obtain a better result with a BU plane.
I guess my point is there are many ways to skin a cat. Just decide which cat you need to skin, pick a tool, and skin it the best you can ;-) In any case, it'll require a few cats to practice on before you get it the way you want it.