The Galli Sport is the Galli Criterium enjoying the dubious benefits of downwards ‘range extension’. The finish is a bit less plush and, in a crucial signal to consumers of the time, the hanger bolt has a hex head rather than an allen key socket. These two changes probably halved the selling price - although how they had any substantial effect on the production cost remains something of a mystery.
The Sport was a decent product at a decent price - ideal for your training bike or for your younger sibling who was just starting out in road racing. Interestingly the pulley cage has a different geometry to that on the Criterium - perhaps to make the Sport more suited to a wider freewheel.