G1 vs G2 - each has one advantage the other doesn't have. In the G1, the trigger is both smoother and user adjustable. In the G2, it is stiff and non-adjustable.
In the G2, you can lower the hammer, then recock it and shoot. In the G1, once you have lowered the hammer, you have to break open the action in order to reset the cocking mechanism before shooting.