Picking an Auth Library

[eluser]Dregond Rahl[/eluser]
iv been checking how different libraries are preventing against brute attacks, i found that although using a DB to track login attempts is good, it seems abit unnecessary, also using Ci sessions, what if smart bots can play around with the cookie value. Why not use both a PHP sessions and CI sessions to monitor login attempts and compare them incase its an attacks? any disadvantages ?

Also from what iv seen "The Authentication Library" is one of the best, but lacking alot of features. Security wise its good and coding is well done, a few mistakes here and there but not too much of an inconvenience. if it had more group controls and such it would be one of the best. Also have to make the admin account un-deletable.