That D3O stuff is the mutts. I used to sell laptop, tablet and mobile cases that had the stuff inserted. Got to play with it's raw form (gel/pate) and it really is amazing. Search Youtube for vids of people putting their hands in the stuff and then smacking it with a hammer
I went with the ones you recommended on the eBay link. I really wanted the d30s but they were about £60. Couldn't justify it having just had Xmas. Maybe next year!