Reliable Multicast (PGM)
Good - Updates Thousands of Subscribers in a fraction of a second.
Good - Optimistic Algorithm - Proven in Industrial Environments.
Good - Useful for More Data Oriented Applications
Good - Guarantee of Order of messages from a single publisher
Bad - Increased Latency over Unreliable Multicast.
Bad - Uncontrolled streams of Data - High-Volume unsegmented bands of data. - Can overwhelm receiver..
Bad - Difficult Addressing Content - Unclear Authority on Naming
Bad - No Security, I.e. Authentication of Publishers