These two spfs take different paths to a similar destination. Both formulas include solid hydrating ingredients, and the overall scores reflect that — the gap here is genuinely slim.
Murad City Skin Age Defense Broad Spectrum SPF 50 brings Tocopheryl Acetate, Avena Sativa (Oat) Kernel Extract, and Retinyl Palmitate as actives, while striVectin Hydration Multiplier Hyaluronic Acid Face Serum with Ceramides relies on Bisabolol, Oryza Sativa (Rice) Bran Extract, and Allantoin. Both approaches have merit, but the positioning and supporting ingredients make the difference.
Both sit in the premium bracket, so value comes down to formulation quality. Murad City Skin Age Defense Broad Spectrum SPF 50 gets the nod here with its 8.4 overall score — you're getting more for a similar outlay.