Well, I can't say Johnny's not a barker. He will bark and growl at the birds and squirrels in the yard from his view out the window. When I'm upstairs taking a shower, I can hear him barking and growling at who-knows-what and he barks and growls at the TV during certain commercials.
He wasn't much of barker or growler when we first got him at 3 months old but as he's grown, so has his voice.
Barker or non-barker, I just find him adorable.