I’ve been using them for about 15 years now. Started when I self hosted at home with the free service and even though I moved to a VPS I still use them ($32 USD / year, dedicated TLD, dedicated IP). I can add redirects, temp static landing page, etc etc.
I’ve had a SINGLE outage of their service in that time.
They also have free services as well, dynIP clients for Win & Lin, and their shit works. Most DD-WRT / OpenWRT images also support it.