It matters a lot—it sets the entire foundation for your design decisions. Think of it like this: a goal-oriented persona is about what the user wants to achieve (e.g., "complete a quarterly report in under an hour"), perfect for productivity or consumer apps. A role-based persona is defined by their job title and responsibilities (e.g., "Financial Controller who approves budgets"), crucial for enterprise software where workflow and permissions are key. Choosing wrong means your features might solve the wrong problem. A great guide on UX personas breaks down these types with clear examples. It helped me realize that for our internal tool, we needed role-based ones to map complex approval chains, not just user goals.