but I wonder how representative patch 9 is of the final reaction system?
We don't know. What we have in patch 9 feels very much to me like a proof-of-concept of a fundamental change to the reaction/interrupt system. The new system is certainly not implemented consistently for all the things you'd expect. If I had to guess, I'd say Larian - who we know were initially sceptical that a more detailed and complex reaction system was desirable - implemented what we have in patch 9 to test the waters.
As far as I know, the response to this change in direction has been overwhelmingly positive, so chances are we will see something very like the patch 9 system in the full game but hopefully taken more advantage of for other reactions and things (like sneak attack) which could be handled as interrupts in the same way.
