I've been rotating the Pro's and the Free's for the last little while. I've been using the Pro's for workouts and the Free's for easy and long runs. Originally I was just using the Pro's but was a bit dubious about cushioning so I got the Free's for off days becasue they're a bit more cush.
First off, the Adizero Pro's are God's gift ot Earth. Never a problem with them, feel great, super minimal, all that stuff.
About the Free's... well, my experience with them has been a bit sketchy. They felt great for the first month or so of use, but after a while my forefoot started getting sore, achey, and all around tender. It seemed that the contours of the Free somehow rubbed and aggravated certain points on my foot... anyway I've had to give them a rest for a while. I've returned to using the Pro's for everyting and they've been great. I've found that I didn't actually need the cushioning in the first place, as the whole concept of minimalism is to get the nerve endings on your foot to better sense the impact and therefore stimulate your body's own shock absorbtion mechanisms... a process which is greatly inhibited by chunky "cushioned" trainers.