Interesting conversation on Twitter recently – basically Especs and NBS were mentioned as possible methods of linking specifications to Revit. What method do you use?
We currently use BSD Speclink and I have messed around a very little bit with the Linkman-e, which is a connection to the spec software from Revit. Its very promising, but your library needs to be managed to truly leverage the link efficiently. We're working on cleaning up our library before really looking to implement- @jrostar
Steve Deadman @SteveDeadman
Benjamin Malone @BenjaminPMalone 
We currently use BSD Speclink and I have messed around a very little bit with the Linkman-e, which is a connection to the spec software from Revit. Its very promising, but your library needs to be managed to truly leverage the link efficiently. We're working on cleaning up our library before really looking to implement- @jrostar
We are using E-Specs…I have been blogging on this topic at archfuse.blogspot.com As Jason wrote, it's a lot of work, but we are finding it worth it.
Feel free to join in on the Revit Genome Project.
http://forums.augi.com/showthread.php?134352-Revit-Genome-Project