After dealing with them while working on a client’s website, I can’t, ingood conscience, ever recommend 1and1.com as a domain registrar or DNS host. Creating, updating, and re-naming CNAMEs and A entries take an extremely long time, with some users complaining of times over 72 hours. This is not taking into account propagation time at all, this is just how long it takes for them to update their own DNS entries on their DNS servers.
We are going on a few hours for my client, but even that is absurd for just updating an entry. Hopefully once we get to the point where DNS propagation is happening, it’ll move quickly.
Furthermore, you’re limited to 5 sub-domains, which is an effort to rope you into one of their more expensive services. You also can’t do wildcard subdomains.
tldr: Do not use 1and1.com if you are impatient or on a tight deadline. CNAME/Host entry updates take anywhere from hours to days, minus propagation time. They also artificially limit you to 5 sub-domains, and no wildcards at all.