Generally I think brick is more traditional, stacked more modern. I am not sure which will be less busy - that will depend on your tile setter and how good they are at laying out the tiles more than if they are brick or stacked pattern, IMO.

I vote for brick, also depends on how thick the grout lines are, as well as matching the marble veining, so the lines will disappear.

Large format tile cannot be laid in a traditional 50% offset pattern. There is too much lippage. The manufacturers all tell you to do 1/3 offset if you want an offset pattern. Otherwise, do a stacked pattern.

My daughter used 12x24 porcelain Carrara tiles on her walls and 24x24 on the floors. She opted for a stacked pattern on both. Her tiler did a great job of matching up the veins in the tiles so that they appear to flow effortlessly across the walls and floor.
I have seen quite a few bathroom pictures with marble/marble look tiles were no effort was made to match the veins. IMO they look rather frenzied and haphazard.
I may be wrong but it seems to me that it might be easier to make the veins match up with a stacked pattern.
You might want to try laying out some of your tiles on a floor. Do both patterns and see which looks best.
Here is a slightly out of focus shot of my daughter's tile

This post was edited by badgergal on Mon, Nov 10, 14 at 18:54

Thanks all! My tile guy said he had to use a 1/8 grout joint.