Dumpster Diver firsthand experience
I am going to add to the confusion by saying that the DD is currently my favorite east coast board! Here's are a couple of items:
1. The DD is not really a groveler. It is a blast in waist high and I have ridden it up to 1 ft overhead and like it in both. I do not like it in knee-high, but then there aren't many boards that make knee high very fun.
2) However, the DD will catch ANY WAVE you paddle for. I like that it has good float without having the horrendously bulky rails that you find on many CI models.
3) As a former competitive surfer, I think the DD is geared more towards vertical surfing than either the Neck Beard (I agree with the marketing gimmick statement) or the motorboat. If you're an advanced surfer that likes to go top-to-bottom, the DD is your call. If you're intermediate or lower, then the others might be more forgiving.
4) Finally, FINS!!! I was riding my DD with the standard Merrick template fins and decided to invest in something radically different. I bought the Nexus-H3 (FCS) and HOLY *crap* did it enhance the drive of the board. And don't think you have to drop $100 on fins. Just pull out your power sander and sand the rake (evenly!) off of them until they are giving you the snappiness you're looking for.
If you decide to pick up a DD, go a solid 2 in shorter than your normal board.