I think diffferent dogs, different personalities, and I think it does depend on what you mean by affection. I think many people incorrectly interpret what counts as affection.
We had a WGSD rescue that was content only when she was with people. All day she'd stay right by you, snuggling on your feet, and if you'd leave the room, so would she. People who visited would say "Oh wow, she really loves you". All this "affection" was a result of weak nerves. She had bad seperation anxiety, and was following us around and staying close because of fear or losing us.
My current 2 are West German workinglines, and very affectionate, but definitely not snugglers, definitely not lay at your feet and enjoy time watching TV kind of dogs. They love me best when I have a ball and we're outside playing. They don't really like to be held, they like to move. But they're big kissers, I'm talking knock you down, jump into your lap, happy squiggly butt kiss you in the face kissers. And when I leave for work in the morning, and I say Goodbye to my male in his crate he shoves himself up against his crate wiggling to get closer to my fingers to pet him and licks my arm the whole time...
Working Lines: Affectionate in a calm soothing way? maybe not. Affectionate? Defnitely!
And Ditto to everyone who said the bond is best in dogs your actually train. You and your dog understand each other so much better when you've gone through a process to communicate.