I recently worked with a client to transfer authoritative control of one of their domains to AWS Route 53 and it was a minor adventure.
It was trivial to setup the hosted zone in Route 53 and import the zone file, although not all records were created properly. In particular, the MX records that were referencing a provider email service were created with the client’s domain appended which resulted in invalid MX records and a failure to receive email. Verify your imported records!
Another significant issue was that the CNAMEs returned by AWS Route 53 were apparently not consumable by the common resolvers used by the clients we were using and resulted in host not found errors. Dig clearly showed that the response was valid and returned the proper values but ping, scutil, and host were unable to resolve records which references CNAME entries that were ELB DNS names. This issue was resolved by creating an “A” record alias pointing to the ELB for each CNAME that we had been using with the registrar DNS provider.