If your hose were NOT firm, I'd be concerned. The benefit of a closed/pressurized cooling system is it raises the boiling point of the water/coolant.
Also, your your upper hose can collapse when the engine cools(with the cap on, of course). The cooling (contraction) of the coolant can cause a vacuum in a closed system. That's why there is often a "spring" in the lower hose...to keep it open.
I'm a hobbyist. Not a professional. Don't be hatin'!
