neither for me.
I prefer to buy a dog breed that I know exactly what their personality will turn out like....just bought my second whippet yesterday after my darling old dog, who saved my life, died several months ago.
Have bought pedigree dogs now for 15 years as I like to know what I am getting.
Also, I tried to buy one from a shelter but sent about 6 emails and only one replied. I would not go to a shop either.