Introduced to these by Catherine Madden, who's a brand ambassador, we used these books at the Wye River June 4-5, 2018 meeting. Folks loved them.
They're expensive — they ship from Europe, and they use Neuland markers — so they're not for everyone. You can hack together something similar by investing in whiteboard adhesive and putting them on clipboards. But the Betabooks are nice, their folded Moleskine-like design is cool, and they really delighted people.