It was a bit a saga, getting my OookStar. I placed an order on May 1st, and Sean surprised me by shipping it three weeks ahead of schedule, in late May. However it never arrived. Sean made up another one for me at no charge (kudos to him for that), and I received it a few weeks ago. I've since been too busy to take it out, and my next scheduled trip isn't till the end of September.
I do have a little experience with Chikara to report, however. I also ordered an OookTub made of the material, and I received it in time for a June trip. It's somewhat lighter than silnylon, packs up nicely, and doesn't feel clammy to the touch. I can't really comment whether it's less slippery than silnylon though, as the OookTub is almost the same width as my Synmat UL7 LW, and the bathtub walls kept the pad in place.
Sean's craftsmanship is excellent, and his designs are well thought through. The carbon struts in the corners of the bathtub floor really help it to keep its shape and keep the slop out.