A few pioneering D-Star programmers (Scott, KI4LKF, and Jonathan, G4KLX, Hans, DL5DI, and others) discovered that callsign routing updates were sometimes taking upto 2 hours. These same guys ran into programming road blocks that the closed nature of the Icom/USTRUST/K5TIT trust that led them to the development of open source alternatives.
Jonathan Naylor, G4KLX recently created some statistics on the size of the ircDDB network against the USROOT based network.
The first thing to note is that the ircDDB network is larger in terms of gateways than the USROOT network. In most countries the number of gateways on the ircDDB network is greater, sometimes significantly so. With the rapid increase in numbers on the ircDDB network these numbers will increase further.
I feel that one of the reasons for this is that the ircDDB network is open, and encourages experimentation and open source. This is in contrast to the USROOT network where opaque and undocumented protocols are in use, yet some still stick to the Icom G2 system, claiming that it is somehow superior! Would these people claim that installing commercial software is more in the amateur radio spirit than home brew and documented software?
Just as an aside, take a look at http://www.va3uv.com/Vulnerability.htm.
Please feel free to distribute copies of this e-mail to anywhere you like, as long as you keep the numbers in the table the same of course.