My hair does flatten after I have been to the hairdressers and so I don't expect miracles but the BBh certainly makes a huge difference. My hair is fine and flyaway and the BBH makes it smooth and bouncy if not voluminous.
My best hair buy ever...i want the small barrel one now.
You could try spraying a root lift spray in the roots before using it. V05 do a good one. I do find the BBH is great for stylish swishy hair but it doesn't give you volume at the roots , well it doesn't for me. I have the small barrel one as well.