Strata vs. Callaway XR — what's the actual difference?

Reviewers describe the Strata as the entry-level Callaway-branded package set focused on value and forgiveness, while the XR 13-piece is positioned as a step up with more current iron and wood technology. Community discussion suggests the XR plays closer to a 'real' Callaway bag, while the Strata is more clearly a starter kit you'll outgrow.