To be honest, I can't say I've noticed a HUGE difference with the SubDude. I know that, with the 500, at times, I still can feel my floor shake (or, at least, that's what it feels like). However, that shaking could be much more pronounced without the SubDude. Also, it gives me peace of mind in that I feel, I'm doing my best not to disturb my neighbors. For $50, I feel it's worth a shot, but I can't guarantee the results. Craigsub uses one. PM him for a more educated opinion.
"People generally quarrel because they cannot argue." - G. K. Chesterton