Hi there, its some years I am working on PJON:
It's a communication bus system for Arduino that supports 255 deviced on a single wire speaking in single or multi master approach. Very fast to use and with a decent practical speed (the fastest mode is 39600 baud/s). Was originally design on 0.x version.
I worked this week end to bring the library compatible with the new IDE 1.x
What I sadly noticed that something slowed down in the program execution.
And with the same testing code i get 15% slower communication speed on 1.x not something
enormous but for sure make me curious to understand how can an update slow down by 15% 
To come back to nearly the same performance I had to modify timing in any way that shows that the reading and writing a digitial pin seems slower.
I am using digitalWriteFast to have a faster digital pin change execution.
Maybe the solution could be contained there but is quite too much complicated to find the needle https://github.com/gioblu/PJON/blob/master/includes/digitalWriteFast.h :o
In any case I hope you will try the new library if interested!!