Customer sites often choose storage related technologies to ensure recoverability for large databases. I've been involved several times in recovering production databases from a BCV or SRDF backup. Mounting the storage copy back on the production server was done usually in about 30 minutes, after a period of deciding what to do that could take another 30 minutes to 1 hour. Then we needed to apply the relevant redo logs, that required a time that sometimes was of several hours.
In my opinion, for sites requiring maximum availability storage snapshots do not provide the best high availability option.They are excellent for building up report databases that are refreshed every day, or for cloning test, QA, development or training databases from production.
10g Data Guard provides the most efficient environment for disaster recovery, it can be configured in several ways to match different sets of requirements, and, together with RAC conforms the Maximum Availability Architecture, that ensure the maximum levels of service.
Configuration and management of Data Guard was made simple through the interface that Oracle Enterprise Manager Grid Control provides.
Still it can also be manually implemented and managed with some training.