Oracle backups using Snapshot Technology

We're looking at implementing a new enterprise backup solution.

Is anyone using "snapshot technology" to backup your oracle databases? If so, could I get more info - O/S, database version, database size, timings for putting tablespaces in backup mode (database mode if 10g), SGA size, good things, lessons learned, comments or thoughts? Have you tested the backup, recovered or refreshed an environment using this technology - any issues?

What about snapshot vs RMAN - any comments?

Thanks in advance.
Dianna Gibbs
Children's Medical Center - Dallas

--
http://www.freelists.org/webpage/oracle-l