Stained glass windows above my (other vote) bathtub.

None of the above.

I think, for the bathroom, for me these things are down further on my list.

My order of priorities would be:

Spa-like environment

Spacious shower with a place to sit.

A seriously large tub

Easy to clean tiles / seriously sealed grout and not white

Plenty of storage space

Plenty of room around the toilet - no cubby holes for me. Had one. Hated it.

Sink bowl needs to be big enough - have had one, which overflowed easily and where you couldn't fill a basin.

After that, I get to your list.

Plenty of lighting with interesting fixtures and a seriously good quality mirror. This is where I look in the mirror and need to know what is going on.

Stained glass windows add beauty and a hint of privacy without destroying light if you have a good enough window, but I don't want it messing with the natural light of the room.

Double shower heads is the one thing I would have to ponder. Mostly, it isn't necessary when they are that far apart. There are two stages of life when it may be useful. One is younger people showering together romantically or to get ready for work faster. I am older than wanting that anymore. I like my own space so unless it is aiming at me from both sides, I am not finding that feature all that valuable and if it was aiming from both sides, I might be worried about water usage.

Thanks D.L for your wonderful list, all of these features are great for the perfect bathroom! We completely agree with your view on the stained glass window - beauty with a hint of privacy, great description. Keep up the good work!