Tile. Fiberglass just feels cheap and oogy.

Here’s an idea, though. If you’re re-doing the bathroom, build a sealed pan with a slight lip at the entry door, and a slight drop towards the shower, and the drain at the lowest point. Tile over the sealed pan. No need for a shower stall at all, though you can keep glass walls for effect.

Shower stalls are an outdated idea in my book.

Aquaglass flexi-flyer shower stall? Maybe for a rental, not something I’d want to have where I actually live and shower. Then again, my current bathroom is exactly 4.5′ by 6.0′, so maybe I’m not one to talk.

It’s a smart design even if it’s not used for handicapped people.
(a) you can wash the bathroom floor easily.
(b) if water splashes beyond the curtain or enclosure, you don’t get water dripping through the downstairs ceiling since the whole 9 yards is sealed
(c) you can change the shower configuration as much as you like without doing much remodeling

Don’t know why all new bathrooms aren’t set up that way — for new construction or a gut renovation, the additional expense is approximately zero.

As an aside, when I traveled in Japan, I encountered a couple homes/apartments where the shower was an entirely separate wet room, accessible from the rest of the house rather than from the bathroom. Smart design — keeps the moisture away from everything else, and allows one person to use the terlit while the other showers. Also would get warm very quickly once water starts running.