First we will look at 2 pics then a point form list (but the pics show my preference best).
This is a pair of red shorties using Katrina's. Notice the crotch droop? Yes they cover his fluff bum but this pattern fits front and back the same and even a cloth diapered bum isn't as fluffy up front, even with the diapers soaker folded to catch boy pee.
*took both these pics this morning in the same diaper for best illustrations.
Katrina's accommodates fluff bum by width.
•MB is more narrow where you add the waist band this makes the waist band fit the waist better, especially if at the age where baby transitions to toddler and slims down in the tummy with all that running around.
Katrina's does not narrow at the waist and I always needed to re-size it.
•MB grows with the child for a longer fitting time
Katrina's sizes are less accommodating
•Katrina's have an optional second layer in the wet zone
MB does not but I have added one. It wasn't easy but it is doable for a more experienced seamstress or someone with a lot of patience. Alternatively you could felt the wool (which will mean the item won't fit as long) or use a thicker sweater or interlock. I have a pair if interlock shorties that didn't need the extra layer.