most of the floor is oak hardwood and a few rooms are tiled so i'll be using marble saddles where they transition. Not sure what size width to choose, walls are standard 4 1/2, doors are 1 3/8. Not sure if my ideas make sense or not, I'll use a bathroom as an example. If you have hardwood floors leading up to a bathroom (or any room with tile) and the door is closed, should you see the marble saddle protruding into the room with the wood floors? The wood and tile floors are very close in height. I figure 1 3/8 is too narrow, most sizes seem to be 2" or 4 - 4 1/2", so I'm probably either going to go with 2" or 4 1/2".