absolutely worth it if you're a songwriter or enjoy playing funk guitar.
Be patient. It starts a little slow, but once Nile gets into voicings and harmony and how he simplifies complex ideas you'll realize how good this is.
For reference, in case you don't know who Nile is -- He was was a session guitarist in NYC and played with the Sesame Street band in his teens and then began work as the house guitarist at the Apollo Theater. He has also written a slew of number one hits as well as produced hit records by the likes of Madonna, Duran Duran, INXS, David Bowie and plenty more. Plus, he's just funky and damn good.