Your list is good but here is a couple of thoughts:
If client is using version older than 11.2 then you still need to add several IPs in TNS entry (even server is SCAN capable) .
This is because the SCAN was introduced in version 11.2.
There is also new features for SCAN in Oracle 12c:
- SCAN and Oracle Clusterware managed VIPs now support IPv6 based IP addresses.
- SCAN is by default restricted to only accept service registration from nodes in the cluster.
- SCAN supports multiple subnets in the cluster (one SCAN per subnet).
Here you can find good document about SCAN:
Thanks Simo. I was aware of the pre-11.2 client issue. I just wanted to focus on benefits of SCAN. Thanks for listing the 12c enhancements. I read the PDF document before and have a copy of its old version. The new version has expanded a lot. The support for multiple subnets may be useful in our shop.
I'm going to post a message about overhead of SCAN and ask for comments.