some application now using sqlserver, after the install and learning,sql server is easy using under windows,but the performance and stability less than oracle
sql serve2k with sp3a, easy with using and performance tunning
oracle 9.2.0.6, difficult with using and tunning,but stability is more much better than sqlserver.
as database cluster,Oracle is much more better than sqlserver with RAC.
maybe my opinion is not equity,as oracle dba 4 years,and sqlserver dba not more than 1 months.