I think polarized lens is better than photochromic Lens because polarized lens can reduce the glare while photochromic Lens can't. What's more, photochromic Lenses don't get dark when you are in the car and the color of photochromic Lenses will change slowly and fade away over time.
Both of them can give 100% UV protection. If you drive a lot, I would suggest you to get polarized lens. They can reduce reflective glare which photochromic does NOT. The photochromic lenses will start to fade in 2 years.