Hi Don,
What size SD has been discussed on this forum and there are many opinions. I guess it is up to the individual.
I personnaly buy nothing larger than 128. This holds my complete library of styles, custom panel setups, panel setups and more.
I use another for miidi and performance.
I back up both with 2 CDS each as insurance.
I am sure others will share their ideas.
Alec's manual is a must and dealing with Walt Tenay has always been a pleasure.
Fran in Florida