You could set up and run your own DNS servers, instead of using Register.com servers - it would give you more control over your name resolution and you will not be at the mercy of the performance (or lack thereof) of the Register.com servers.
Even better, let one company run one of the two DNS servers listed in your domain registration, and let another company run the secondary DNS. It is the old principle of not putting all your eggs in one basket. You have created a single point of failure when both DNS servers in your domain reg are run by the same company. The whole reason that DNS servers are listed in pairs is to give you the wise option to dual-home your DNS on two different DNS server networks.
And of course, we would be happy to run secondary DNS for you and you can keep your primary at Register.com. As an alternative we would be happy to transfer your domains to our registration services and run your DNS for you, dual-homed. At your estimated level of traffic usage we would not charge you anything. Not one user who has registered a domain with us over the last seven years has ever had a registrar-related propagation issue

Do unto others as you would have them do unto you, and sit in with the band whenever you can, to keep your chops up!