I had one in most of the apartments I lived in, but I was always having problems with them and needing to contact the landlord to fix it (some of this was my fault but still). Now that I have my own place I’m not going to install one, I don’t want to spend money if the result is mostly to get to maintain yet another thing, just to avoid shaking a drain trap over the trash every once in a while.
Personally I wish there was a way to filter out all the comments by people who haven’t read the article.