Question Planning a 10-Day Road Trip in Portugal - Porto or Lisbon?

We're in the midst of planning a 10-day road trip to Portugal this spring, a destination we've never visited before. From what I've gathered, direct flights to Lisbon seem to offer the best value. However, Porto has caught our interest more than Lisbon based on various reports and videos we've come across. We're not usually the type to spend a lot of time in larger cities, so we're torn between starting our adventure in Porto or Lisbon. Has anyone here done a similar road trip? How did you split your time between these cities, and what were your highlights? Any advice on must-see spots or hidden gems along the way would be incredibly helpful.