I like it. It grows like crazy and makes a good hideout for fry. It is pretty messy until it gets settled in. It is a pretty inexpensive plant that fills up a lot of space with green. I leave most of it floating but plant a few bits here and there. Just don't bury it too deep... The part under the gravel may rot.
So far so good with the hornwort. Thus far it hasn't made a mess and it is staying rooted. I won't hold my breath until it has been there for a few months. It seems to be growing so... Hopefully, it is in a good spot and it will take off. Sadly, I have had similar experiences with other stem plants that look so lovely for a short while and then go south quickly.