I would say one con could be any knuckle head can get their hands on one and not use it correctly and cause leaks. But that already happens with brazing anyway.
The upfront cost of one these machines is pretty expensive they are around 3k if I remember correct also the fittings are pretty expensive as well. But I would argue that you would make your money back over some time using it.
pros:
They are much faster.
Looks cleaner.
no need to flow nitrogen.
No need for fire spotter if you are in a confined space.
I am sure there are more I just rambled off a few.