We put wall panels in the shower of our holiday home about 5 years ago. We went for cheap and cheerful white metro brick tile design and they do the job. Easy to keep clean, (no grout), look ok, inexpensive, and totally waterproof as long as they are fitted properly. Quicker and cheaper to fit than tiles but they do remind me a wee bit of the shower room in MIL’s caravan.
Now in the process of doing our en suite and have gone for Multipanel in Calacatta marble. This is a far superior product. It feels fantastic and looks superb. Really thick and solid panels. No grout lines so looks like sheets of solid marble. However it is not a cheap option.
In another bathroom I have a tiled shower enclosure and have a ‘niche’ of shelves built into the wall. It is a pain in the arse. Water always gathers on the shelves and you have to wipe it dry every time or it goes all slimy and smells. This is nothing to do with the tiles. It would still happen with panels. I would advise against built in shelves within the shower area unless you can guarantee that everyone will keep the area clean and dry. Unfortunately my teenage son is incapable of this.
I was dismissive of the panels at first. Thought they were a bit naff but the range available now is fantastic. Marble, wood, slate, concrete, tiles, sparkly, matt, glossy etc. They are easy to cut to plumb in the shower, taps etc. Easy to drill into to fit soap basket, shelves, hooks etc.