l heard the boards were going to be thinner with a different colour than the first game.
The SoS boards are *slightly* thinner than the AtB boards. The difference is not big enough to be an issue.
The SoS boards are more vibrant than the AtB boards. They are still 100% functional, but you will notice the difference when they're placed side by side. The SoS boards are also a tad glossier (which adds to the vibrancy.)
They are definitely completely compatible though.