Sassafras is just between ash and alder tone wise, but way lighter, for those knowing that wood is important, for the others it's just another wood with a fancy name.
It's a wood used by Fender in the very early days and, for example, Eric Johnson's favourite Stratocaster, Virginia, from 1954, has a body made out of this excellent wood.
https://www.fender.com/en-US/electric-guitars/stratocaster/stories-collection-eric-johnson-1954-virginia-stratocaster/0117442803.html
I had a Jazz Bass made by luthier with this wood for the body and it sounded amazingly good, but I had too many Jazz Basses back then.