I think that this discussion is missing an important point.

First of all both the original scheme and Nile provide the basic streams 
implementation.
Let us say for argument sake that they are both equal in design, 
relative complexity and performance.

Now what benefits do I as a user have if I want to implement my own 
class stream like class? Does Traits offer me any advantages, and do 
those advantages scale to larger systems, and long term maintainability?

The number of times I look at an object with a #propertyAt: 
#propertyAt:put: leads me to assume that traits must be good for something.

Keith