Floor-level shower tiled with channels or with a shower tray?

hello dear ones,

Your experiences are also needed here.
Floor-level showers tiled with drains or with shower trays.
What are your experiences? What has proven to be effective.
Best regards, Xinette

We are getting a floor-to-ceiling tiled [bodentiefe geflieste] with a wall drain. However, I have no experience with it yet.

We have tiled floor-to-ceiling on the upper floor and almost flush shower trays on the ground floor. However, we have not been able to use them yet because the shower cabin has not been installed. I can no longer understand why we didn’t have tiles installed downstairs as well, because in my opinion tiles look better and are not more expensive. Cleaning a shower tray is probably somewhat easier than cleaning tiles. I am in favor of tiles because they look more consistent and therefore more spacious than a tray. The drain on the upper floor is at the back wall and tiled, works perfectly (why shouldn’t it?). The tray has a round drain in the corner.

My personal opinion is that a shower tray is better in the long run. Several bathroom suppliers have also confirmed this to me. It is based on the fact that with a tiled shower floor you have to put something like a "drain strip" or at least the drain somewhere. After a few years (since the material shifts), the silicone joint may tear and water can leak in very undesirable places. With a shower tray, you have this problem less because it has a slope. At least that's how it was explained to me. I hope I described it correctly.

And our sanitation guy dismissed that as nonsense (or rather as a sales argument FOR people who want to sell shower trays), because even a shower tray has silicone joints that can crack and where water can run under the shower tray.

So when constructing our tiled shower, I could observe that there is a very large "dish" funnel under the drain grate, which is much larger than the visible "hole." This sits all the way under the adjacent tiles. I wouldn't know where a silicone seal would ensure watertightness here, so that there is a higher risk than with shower trays. Due to a kind of drip edge at the bottom, nothing slides underneath anywhere either. The rest of the piping is then no different.