Originally Posted by
the810
It goes down to how full is the flight. Fully booked Embraer? It will be gate-checked even if it's within the limits. 100 people on 737? You can essentially bring a sink on board and no one will stop you.
That is if and once you dodge the agents lurking in front of security access in VIE who may want to hustle you into weighing your bag. They are, however, mostly concerned with weight and not size IME.
Purposeful steps towards security and adopting a bit of an attitude may help minimizing that risk.