1/2 Size Upright Bass vs 3/4 Size

[mickcope]

I have just started (newbie) playing Double bass in a Bluegrass Band - using an Old 3/4 Bass - the fiddle player suggested that at lot of bluegrass players use 1/2 as they are now bowing and so don't need the size.

Never having tried a half size - is there much difference in them in terms of the volume of output from the instrument?

cheers

Mick