Avoid: they overbook flights and bump you without notice/compensation
My review is for JetSmart within Argentina.
Read the review consensus and avoid if at all possible. Go for the more reliable (if more expensive) Aerolineas Argentinas.
As for JetSmart, they overbook flights and this is a common occurrence for regional flights into Buenos Aires. They don’t do online check in. So unless you arrive at the airport many, many hours early (or just get lucky) then you’re taking a real chance even being able to catch your flight. Flights heading out of BA demand is lower and less severe.
Maybe Argentinians just accept this as the norm, but it’s obviously poor and their review rating speaks for itself.