I'm those more expert than I will weigh in any minute but...
Advantages: Strong, light.
Rod is lighter for a given strength than 1x19 I believe.
It has less windage (thinner for a given strength).
Disadvantages: $, repairability, predictability or inspectability.
It is more expensive, harder to find in far away places and is harder to inspect for impending failure (I'm told).
For those reasons you generally see 1x19 on most cruising boats vs rod although that's not a universal rule. I think the go fast types are looking away from rod and at UHMWPE now.