MP and AIO are different. MP is a *very mild* abrasive with wax in it. It polishes and protects better than AIO. But AIO cleans better, although it does it chemically, not mechanically. If you have some stubborn polish residue (like PI-III MG) or some "road film", for instance, the AIO will clean it off much easier than the MP. The MP works best on a surface that's already clean.
Beading vs. sheeting- must depend on the vehicle/conditions/prep. I use the K twins on my Japanese vehicles, and they bead for many, many months (currently, the KSG is over seven months old and it's still beading, NOT sheeting, despite spot-claying with every wash).
AIO topped with #16 is a very nice, and very easy, combo. AIO by itself offers *very* little in the way of lasting protection, or at least its protection is very fragile- it gets washed/worn off rather quickly.