14nm+ will be just like 14nm.
The only real difference is the CPU's will be "stronger" and more efficient.
So they should require less power to run,
Run cooler,
Overclock better,
The SOC's within them should be able to handle more (so better APU if applied, higher RAM...)
There are a few more differences but not worth talking about.
The main difference for AMD would be, it should be cheaper to make, and better yields so more profit.
This is all true on paper, but doesn't mean it has to happen.
So you could have a "golden" chip which out performs 14nm+.