I'll take Slash over Buckethead for extended listenability.

In 30 seconds you've heard every warp speed scale and lick that Buckethead knows.

Slash has a more melodic style and knows better when to switch from relaxed to overdrive, IMO.

Buckethead has chops, no doubt... but to me he's a Paul Gilbert wannabe and there's only one Paul Gilbert.

Speaking of PG, here's a shred solo of his from 20+ years ago that I'm sure inspired Buckethead:



I'll take Eric Johnson, Vinnie Moore, Paul Gilbert, Yngwie Malmsteen, Steve Vai, John Petrucci and Nuno Bettencourt over Buckethead any day o' the week.