This thread is acting weird... I posted right after the OP submitted, and it is now not here. I posted that in the high end homes I see, if the tile is larger than normal, and there is plenty of space, the stacked looks fine. If the tile is more of the normal size, then I see them laying it out the traditional way. This holds true for both back splashes and floors.

What I have seen lately in higher end homes is that the tiles are stacked if they are large and offset if they are of a normal, or smaller size. This is true for back splashes and bathroom floors.

@Slough Shark we are just getting started with the master bath in our new (budget) build- although we have hired a reputable tiler to do the tile work. 4x16 white glossy subways for the shower walls and grey pebble mosaic for the shower floor. Bathroom floor tile is a dark grey and I am struggling to pick a grout for the floor tile. I want to use the same color for the mosaic and hexagon floor tile. Looks like your floors might be about the same color... could you post a pic of the floor tile? Im considering pewter or dove gray from custom building products. i am now debating choosing rolling fog instead of platinum for the subways after seeing your results!!

You want to take the time now before you start tiling to make sure that you won't end up with slivers at the ceiling and around the window. Also consider how the placement of the bottom row impacts the tile at the tub leg. You want to be able to cut a radius in that tile so that it hugs the corner of the tub going down. If the bottom row is a full tile, then butting the tile below it at the tub leg will leave a big gap. You can avoid this by starting the first row at less than a full tile. Make sure that your tub is level from left to right, and if it's not then cut the bottom row of tiles to fit (so that the top of the tiles is level). This might actually be why you ended up with the curve.