Auralex SubDude

Anyone using the Auralex Acoustics SubDude underneath their powered subwoofer?

http://www.auralex.com/sound_isolation_subdude/subdude.asp

According to the web site:
"Its purpose is to prevent sound from transmitting through your subwoofer to surrounding surfaces."

Does the SubDude really work as advertised?

What sonic benefits have you experienced?