SharDB vs HyperDB vs MultiDB

I thought I'd start a discussion on these different types of "multiple databases"

Here is my comparison so far...

Multi-DB
o Designed for Multisite!
o Split your DB into 16, 256, or 4096 databases!
o Spread them across multiple servers!
o Replication!
o Configurable Reading/Writing prioritization
o VIP partitioning

SharDB
• Multiple VIP databases
• Migrate data to SharDB global or local tables
• Based on HyperDB
• Paid Install Guide on wpebooks

? HyperDB: replication, failover, load balancing, partitioning and more!
• Based on Wordpress.com’s database code
• Replaces a few built-in database functions to create an advanced DB class
• Can connect to any number of DB servers upon inspecting the query
• Supports
o Replication: Read and write servers
o Configurable Reading/Writing prioritization
o Local and remote datacenters
o Private and public networks
o Tables spread across databases/hosts
o Smart post-write master reads
o Failover
o Advanced statistics for profiling

Do you know of any main differences I am leaving out, or another reason to choose one over the other?

Looking forward to an informative thread here
Please Share Your Experience and Opinions!
Thanks for the time and interest!