I have used them twice so far, so I can't judge. Just one of the two was already torn on the side as soon as I took it out of its packaging, so it leaves a small space for clothes to come out.

It is big and you can put bulky things in it. So far, the result is very good and highly recommended

It's fine. A little big for underwear only, but the size doesn't bother you at all in the end.
It has gone through quite a few washes, but it hasn't noticed anything. The zipper opens like the first day.