about DB2 HACMP/HADR/CAS VS. Oracle RAC

I like what Oracle RAC delivers, it's very appealing। ,But,You know, everything has its shortcomings, though sounds perfect।

"RAC provides transparent application failover for reads (if you use Transparent Application Failover and their thick JDBC client), but not for writes."।

DB2 CAS can avoid this by serving with buffering with SQL in CAS server and utilize two or more same databases... I know DB2 CAS will be very new to the majority, but it is. I think it's the real one(from IBM) can be compete to Oracle RAC. more, since CAS is seperated from databases, so it can be configured in various way. It also can support websphere HA.