I had bought another PVC glue from Geistlich but found it was still quite flexible after curing.
So I tried this one instead but also changed the parts I wanted to glue, so can't tell for sure which one is better.
This Tangit glue works as I expected and the final joint feels solid. Waterproofness not tested yet, will update my review and score if not satisfactory.
You need to follow the instructions: surfaces need to be cleaned and scraped using sand paper. Apply a thin layer on each part and glue immediately. Easy and fast.
One surprising fact: when I started to squeeze the tube to let the glue out, I noticed the tube lost about half its volume before getting the first drop of glue! That's a bit unexpected on a brand new tube. So I feel like there is not as much glue in it as it should, but I can't tell for sure if that's the case.