You're right, do what you want unless you know you'll be selling soon and want to be more generic in your choices. If my husband gave me the green light to revamp his 30 year old bathroom (only room in the house that hasn't been remodeled) I'd be using a rustic tile! We built our house 30 years ago and plan on being in it for 30 more years so it's decorated for us :) That being said, there are different degrees of "rustic", don't you think?
Monica

Rustic can be a broad term. I don't know how "natural" can be over. That being said I recently redid two bathrooms and my shower floor choice for one was a smaller tile version than the same for the rest of the wall and floor tile and in the other where I had white tile and a grey abalone mosiac accent I picked a grey that pulled in the color of the accent tile. Personally as I stated in another post I chose what appealed to me yet also felt down the road a potential buyer could be comfortable with the choices.

I think the tumbled rustic look is probably on the way out for any room. Even though I had them in my old kitchen, I never liked them. I like cleaner looking lines and surfaces. If you love them and don't plan to sell to a hip crowd anytime soon, get what you want. The style police won't invade your bathroom to fine you! ;)

processes for cooking and cutting have improved over the last few decades, and this technology has trickled down to manufacturers of tile. There is more higher quality tile. It's more likely to be square, and this allows for thinner grout lines (something 99.9% of all people want). All the other characteristics are more likely to be better now than they were ten years ago. PEI, porosity, glazing, etc.

The rustic look is optional now. It used to be hard to manufacture anything else.

What happens when something is "in", is that it is used indiscriminately. Tumbled marble in a high rise, for example, or brick georgian. It is also knocked off cheaply and over done, so then people start to dislike it, for good reason.

If you think the rustic feel works in your space, use it. What is in style and may work is the handmade, encaustic, moorish stuff. Maybe you can find a good selection there.

I hope not. I am having my bathroom redone with quartzite mosiac and a porcelain that looks like quartzite. I think it depends on the look you are going for. Ours is a vacation home, so anything formal looking was not going to work. I wanted it be casual and comfortable.

I just think it needs to jibe with the style and age of the house. If the house is older, more classic finishes seem to fit. More rustic homes (my parents for example) look great with rough, textured tile and other natural finishes - my choices would look "off" in their home and vice versa.