More flexible configurations (can use LAN interconnect) – Chapter 3.
Single System Image (management) – Chapters 1 and Chapters 2.
Cluster File System – Chapters 2 and Chapters 13.
Performance benefits due to:
CFS and "improved" DRD – Chapters 13 and Chapters 15.
Ability to use newest AlphaServers.
Ability to use newer, faster storage.
Improved manageability – GUI management interfaces – Chapters 5, Chapter 11, and Chapter 19.
Simplified installation/configuration – Chapter 10, Chapter 11 and Chapter 12.
General ease of system administration (LSM, software installation, etc.) – Chapter 14 and Chapter 19.
Cluster Alias (cluster or cluster subset appears as a single machine to clients) – Chapter 16.
CAA for high availability of single-instance applications and ASE-style start and stop scripts migrate easily – Chapter 23 and Chapter 24.
CAA allows resource dependencies, polling and auto-restart capabilities – Chapter 23 and Chapter 24.
CAA advantages over ASE (no need to manage storage in action scripts); more flexible dependency rules provide greater range of failover choices – Chapter 23 and Chapter 24.
Application compatibility (if an application runs on Tru64 UNIX V5.X, it will run on TruCluster V5.X) – Chapter 3.
Great platform for large multi-node database applications – Chapter 3.
More scalable (easier to add members) – Chapter 11.
Support for Fiber Channel multi-path storage access – Chapter 4.
Larger storage configurations – Chapter 4.
Wide SCSI addressing – Chapter 4.
Improved AdvFS performance – Chapter 13.
Clusterized LSM (looks the same as LSM on a standalone system) – Chapter 14.
No requirement for symmetrical I/O configuration among cluster members – Chapter 3.
You'll be cool.