Although this may not be perceived as constructive criticism but freedns is indeed great. It has many features, thousands domains, support for your own domain, perfect availability and it is free. The person behind it seems more interested to provide a free quality service than promote himself.

For anyone building a dynamic IP service, freedns sets the level they should strive for.

Too easy us programmers like to complicate things in order to make them easy. :P

I'm using it successfully with a custom domain. It works great.