I'm Mike Packer, the inventor of the heel less pedal. Uniin, just for clarifacation, DW only makes a 5000 heel less. The 8000 you are referring to is their longboard pedal. Here's a link to the video demo I recorded at the DW factory.
Hopefully, it will better explain the pedal and answer your questions. Feel free to e mail me at email@example.com Buying a pedal is an expensive and considered purchase and I want you to make the right decision. I'm happy to answer any other questions you may have.
I actually have the DW 5000 Heel less pedal and do have a few thoughts...possibly they'll help. This I can tell you for sure, probably regardless of your technique, this pedal will nearly double your power. It pops a pretty good wallup (is that a word?) and I was immidiately amazed at how much easier it made playing doubles. I happen to have a much lighter kick drum foot than most of the drummers I see posting here. That said, this pedal allowed me to instantly define doubles loudly, especially for funk stuff that's quite syncopated. The only downside to this pedal for me- it feels a hair short, so there are a few minor comfort issues. But also, because of the fact your heel's actually hitting the floor, the angle at which to push motion forward is higher. Hopefully that makes sense, but basically because your heel's dropping lower than usual- the angle at which you press down is higher than what you'd typically be comfortable doing. I was, for instance, playing in a cover band and we were playing 4-5 .45 minute sets. My leg, especially the shin (as well as my knee area) was pretty spent because of this. However, most people probably don't play for that long a period so it may be a non issue. 1-2 sets is easy-it's the 3rd, 4th and 5th that'll give ya shin splints! I think it's a great pedal and I only feel comfortable playing it now. Again I cannot stress enough how much easier it is to do the doubles at nearly twice the power...so I love it.