Not sure anyone has yet run up enough miles to have tried this aspect of the program out. But as someone looking for new home for *A earnings at the 200/300% level for J/A (although granted not for all airlines) I had given this program some thought.
But the lack of information about rewards is a problem for making a jump. I guess if you just want *A Gold this program is great, but if you are looking to rack up miles in premium cabins for premium awards, the devil is in the details!
BTW, is there a Gold tier mileage bonus with this program, or do you just earn the flat 200/300% when in premium cabin?