After seeing Ron Saikowski's Terminator Librarian( seen here http://fromthewarp.blogspot.com/2009/05/terminator-librarian-finished.html ) over at http://fromthewarp.blogspot.com/, I have been motivated to make a terminator librarian and give it a try. Before I go on and convert one I want to get people's thoughts and opinions of the Dark Angels Librarian.
Dark Angels Librarians have 2 powers, force barrier and hellfire. Force barrier allows the Librarian (when he takes a wound) to take psychic test and if he passes is treated as if he has made an invulnerable save. This could be very useful, especially when used together with an Apothecary (gotta love that Apothecary)to help shrug off some of those AP2 weaponry. His second power, Hellfire, is a shooting attack with the following profile: Template, S2D6-2, AP D6, Assault 1. Pretty random to be counted on, but it can possibly be a S10, AP1 flamer template. It will probably have games where you wish you took something else and games where you will be glad you took the librarian.
The Librarian also has the old psychic hood that covers the whole table, but at leadership 9 it might not be as effective since most psykers used in tournaments are leadership 10. He is also no slouch in combat with 3 attacks and a force weapon at an initiative of 5.