The pros: it looks good. It's elegant.

The cons: It's expensive. It's a porous stone so it scratches and staines very easily.

Consider a porcelain tile that looks like marble.

Cons: it's hard on your joints and very slippery if you wear dress shoes.

Actually marble floors stand up very well and have been used for centuries.You could even checkout the oversized slabs at Porcelanosa if you can find a tile installer that has used them do not go with someone with knowlwdge of super large format tile. Marble has minimal seams no matter size tile.We have friends in Miami Beach with whilte marble floors everywhere with at different times 4 - 5 dogs and the floors look awesome 10 yrs later. BTW I have lamonate from Germany that looks amazing and looks like cararra marble my big dogs have no scratched it at all .

A picture IS worth several thousand words! Oh my goodness. Makes me cry. Marble, may be best used as a lazy susan on the center of a kitchen nook counter height table and chair dining set??? or as a drop in for rolling out pie crusts in a butcher block counter that rises to meet the arms' length of the chief cook in the house? The prettiest marble I have ever seen, is the Altar at a church I attended Mass at. It was truly elegant. That was a great use of the stone.

Our house came with brand new medium sized marble tiles in the bathroom. I've lived with it a year.

Pros: I love the look. It's light and airy and there's enough natural variation that it always looks clean vs our other bathroom tile that shows every hair or speck of dust.
It's silky underfoot and luxurious feeling.

Cons: Sophie's pics are accurate. There's a small splotch already on one tile; looks like the 2nd to last picture she posted.
There are two scratches already as well, no idea when they showed up or how.
It's a bit slippery.

I love the flooring and can live with these slight imperfections but eventually it'll need to be repaired or replaced.

Thank you all for your comments. Much appreciated.

Ooooooh Sophie! You have new marble patina photos! Love them!

While marble is used in public buildings, those floors are professionally maintained and are not subject to the kind of close scrutiny that homeowners sometimes exercise. I installed bianca carrera floors and walls in washrooms in two of my own homes and with light use they dulled in a couple of years. After that, I moved to honed quartzite in entries and baths.