Your response to DanWaterworth made me assume you were speaking from a perspective that valued STM, but fair enough. I agree; 'typical' programs do not lend themselves to actors; you have to change how you write programs (the same would be said for Haskell, of course).

"consensus" and "a stable view" are things you -definitely- need to concern yourself about if you need such things and are working in a distributed environment, actor model or not.