you should post this on the discussions side. You've posted in the gallery where no one gives advice.

I vote tile floor, but with smaller tiles than 6x6. I've read too many nightmare stories of the pebble floor not draining well leaving standing water in your grout. I do have a question for you: If you don't want alot of grout, why are you looking at a pebble floor? Pebble floors have more grout than even a 2x2 tile floor. Compare the amount of grout (and the varied grout "lines") in tobler's pic above & the amount of grout in my shower using 2x2 tiles in the pic below. The reason for using smaller tiles in a shower floor is that the grout is what gives the traction under your feet to help prevent slipping and falling. The less grout you have, the greater your chances of slipping & falling--6x6 tiles leave very little grout and hence very little traction. You don't have to have huge grout lines either. They can be as small as 1/16". If you're worried about scrubbing, squeegee the walls and floor after every shower then spray an antibacterial cleaner (like Scrubbing Bubbles) once a week on the floor to kill any bacteria that may be there and rinse. That's all the maintenance you will need to do. Tobler has a beautiful shower and from their posts also squeegees to keep it looking like new. Note: The shower floor was not completely dry when this photo was taken so you may see some variation in the grout color. When dry, it is all a Pearl or cream color. When wet, it turns more of a light brown color.

Personally I prefer Option 2, but I live in the Pacific Northwest where in the winter nature provides plenty of gray every day, so I wouldn't want dark gray floors (no need to match the sky on a dreary February day). If you live somewhere less prone to nine months of clouds, either could be great. (Note - none of this is meant as a criticism of the Pacific Northwest - I love my gray days and am waiting anxiously for their return. Enough of this sun business).

That's really a personal preference. Contrasting grout and smaller tiles will increase the visibility of grout lines - it will introduce more pattern in the space, which can read as "busy." If you prefer a more tranquil/simple space, I'd stick to minimizing the visibility of grout lines - either through matching them in color to the tile used, or picking larger tiles. Entirely personal opinion, but I default to smaller mosaic tile floors in my own bathrooms - grout choice varies. Disclaimer - I outsource cleaning duties. I also avoid large format tiles on walls (they aren't really my style) but others love them, so again - personal preference. Again, just my opinion, but I'd probably do a smaller gray hex (like 2 inch) with matching grey grout. My only recommendation if you go with a marble and white/grey color scheme with your tile is to pursue color and warmth via other finishes - avoid sticking purely to white or grey everything. Pick a wood vanity, or a painted one with color. Otherwise, these baths have a tendency to look like mausoleums to me. The color of the grout you use on the walls, it should continue onto the floor so its connects both colors and is seamless. I disagree. You can totally use two different colors of grout in a space - especially if the tiles themselves are different colors. I've done this multiple times with good results.