[1] Blues writer Stephen Calt describes it as "a Two-Step piece marked by fiendishly fast playing [in] an eight bar arrangement comprised of single measures.
[2] James's version is noted for its irony, as the upbeat melody and repeated refrain of "I'm so glad" are set against lyrics that describe restlessness and romantic anguish.
[3] An album review included: "it's the rampaging 'I'm So Glad' that illustrates how far they've come; compare it to the original studio version on Fresh Cream and it's easy to see just how much further they're stretching their improvisation.
[3] Skip James was pleased with the new interpretation of his song and remarked: "That piece is absolutely gonna stand.
"[2] Deep Purple added an intro and titled the song "Prelude: Happiness/I'm So Glad" for their first album Shades of Deep Purple (1968); "Jon Lord's organ flourishes, weaving classical riffs, and unexpected arabesques into "I'm So Glad," which sounds rather majestic here", according to AllMusic's Bruce Eder.