If I ever build my dream house (or even get to gut out the master bathroom of our current home), at the very top of the list of "must haves" is a shower with slab walls. Our current shower is tiled, and while I like how it looks, keeping it clean is the bane of my existence.
A typical morning might find me scrubbing the grout with the toothbrush I keep on the soap dish, or going at the floor with the scrub brush that stays inside the shower for that purpose. It's never ending.
And so I want my shower walls lined with seamless slabs of marble or granite. Sounds pricy, but I'm convinced that a careful shopper could actually realize some savings. Tiles can be terribly expensive, and the labor to install them even more so. Surely finding a good deal on a slab would ultimately mean construction savings. And if not, well, my time is worth something after all.
What a heavenly bathroom!