I would also like to know on what criteria the survival is rated.. With reagard to WinMX, do they mean WPNP or OpenNAP? It doesn't stand a chance? Cmon now..
Soulseek should've been in there.. it's one of the best around, especially it's 'Download Containing Folder' and the cool 'Wishlist' feature. I've no idea how scalable the network is and strongly suspect it could be shutdown easily as you are not allowed to run your own servers(for the time being) and their system of 'Download Privileges' for a payment.. read their
FAQ