To each his own! I would just caution you to keep the tile as neutral/flexible as possible. We did our bath over in white subway tile. I wanted "accent" added with the design of the laying of the tile---basket weave--boarded etc. At the last minute I caved and allowed DH to add a strip of those glass tiles that are all the rage. My issue is now all due to one dang strip I am STUCK in a color palate. The reason I chose the white was for FLEXIBILITY as time went on!!!

I think feature walls (in tile and in paint) tend to be trendy and won't necessarily stand the test of time - not a big deal when it's paint, but not so great when it's tile! I would opt for simplicity if I were you.

When we tile, we go for simplicity and timelessness because we don't like re-doing things and plan to be in our house for a long time. But if tile features or renovating your spaces every so often makes you happy and/or you're not planning on being in your house for decades, go for it! And actually, two different shades of grey on the walls and floor doesn't sound like it would date the space any differently than one, or even make the space look less clean and simple. I like the simple lines of your bathroom and think it will look pretty either way.

Arcy, I wonder if/when you get tired of the glass tile strip how complicated it would be to swap out just that strip. I've never tiled myself so am not sure how hard it would be to demo a strip and replace it with something classic (without destroying the tile surrounding it), but it might be a possibility. Either way, I'll bet the glass tiles will be "in" for a long time yet.