FRench guinea, mine are huge.

[animals1981]

ARe these french guinea, they are taller than my RIR hen. Also they are quiet.

 

[sawilliams]

They do seem big. I remember when mine first started getting to thier full size I thought they would be much bigger then my hens. They are taller because thier neck and legs are longer but overall they end about about the same size. As for quite... it won't last long. Sort of life a rooster once they find thier voice you'll know it. The reality loud calls are usually reserved for warnings but can carry on for a few minutes at a time as they all join in the call.