It can either look really dramatic or too dark, depending on the size of the room as well as your other components. I've attached a couple of images of our work using dark tiles, the smaller bathroom we have surrounded the bath with dark tiles but then balance it with an extra large mirror to bounce the light around the room. The larger bathroom we have taken the floor colour way onto the wall but used a different texture on the walls for drama. Hopefully this gives you more of an idea but you shouldn't to nervous of the room being dark, it's where you can create a contrast as well as textures. Look forward to seeing what you go with in the end.

Have you already sourced your tiles? I would expect most tile stores could help you find the edging tiles which I think are typically termed 'pencil' tiles for the style you have shown. We used bevelled subway tiles in our DIY ensuite. In hindsight we would have aimed to finish the brick pattern with 1/3 and 2/3 sized tiles (like in your pic 1) rather than full and 1/2 (pic2 and 3) to give a more even edge thickness/profile... Might not suit and we didn't use capping tile (I lost that arguement!) so it is probably more obvious in our bathroom, but just something you might like to consider.

Option 3 has a terrazzo-look tile which references the previous and original bathroom. The concrete look tiles will date, and look quite daggy in ten years time. Best of luck, Dr Retro of Dr Retro House Calls

With a small bathroom like yours, and large format tiles the joints between the tiles are actually more important than the tile. You want to make the bathroom seem bigger, and horizontal joints will help this. Don't lay in a traditional brick pattern, where every second tile is offset from the tile above as this makes it visually busy. Go with a standard grid pattern, with your rectangular tiles laid horizontally. Try to get your tiler align the joints in the floor tile with the joints in the wall tile. By keeping it as plain and simple as possible you will perceive the bathroom to be bigger. Best of luck, Dr Retro of Dr Retro House Calls