It was absolutely necessary to learn 1 1/2 fret, Bing Futch was also helpful
Just in case I get a 1/1/2 fret I bought Aaron's book. I thought I'd explore it and found out I'm now excited about getting that 1 1/2 fret added. I used the book to partially air play the fret I don't have yet. It made me want one because I loved the tunes.
I especially enjoy the blues licks and the ordinary song tabs with the blues flavor that the book includes. I'm not sure I'm advanced enough to apply much to my other tabs but I understand the idea and like playing his arrangements with 1 1/2 frets.
Aaron makes the 1.5 fret accessible. Definitely worth the purchase price for the confidence it inspires!