Ranked in these QuestionsQuestion Ranking
Pro Detailed setup instructions for a wide variety of OSs
Duck DNS includes step by step instructions on how to set up their service on a wide variety of operating systems. There even are instruction on how to set it up on raspberry pi, mikrotik routers, tomatoUSB as well as multiple ways for Linux, Windows and OSX.
Pro DuckDNS sync app for Android
Con Lacks advanced functionality
In an effort to focus on simplicity, Duck DNS lacks features such as custom domains, url or port forwarding and uses just 1 domain.
Con Difficult to use on some routers and NVRs
Routers and NVRs that give you set options (that don't include Duck DNS) won't work with Duck DNS. Apparently Duck DNS claims they support DynDNS or something of the sort, but the information it gives you, there's nowhere to plug it in in these boxes.