Pros; If you don't then you will have plaster falling off eventually, The wire provides the same "structure" as Lath boards did in old houses, something for the plaster to get a grip on so it stays put.
Do it once the right way or you will be re-plastering at least once.
Cons; It does take a little time to put up and then there is the expense of buying it.
These are off set by the amount of time it will take to clean up the dried plaster when it falls off the walls and then the mixing new batches and applying them after you have corrected the problem.
We love visitors, that's why we live in a secluded cabin deep in the woods. "Buzzard's Roost (Asnikiye Heca) Farm." Promoting permaculture to save our planet. you can call me Dr. Redhawk