Has anyone tried the new Dayton Audio PUCK shaker? I currently have 4 of tha Aura Pro's. With the DA PUCK being half the size of the Aura (or about the size of a hockey puck) I was thinking it may be useful in those areas where little room is available...ie the backs of sofa's and recliners as added effect. Don't know if the small size might make them ineffective. What's everyone think?