Check out 475 Building Supply's rebuttal to GBA's issue with unvented assemblies below. While I think more long term data from more situations would help confirm the modeling, I'd say 475 handily takes this round of the debate with a well substantiated case for smart membranes.
https://foursevenfive.com/greenbuildingadvisor-smart-membranes-475/
https://twitter.com/ClarkChapin/status/699652658206932994
Image copyright 475 Building Supply