Yep. Several years of multiple S4s using Strat/Roc-Euro at the limit of performance with success and all of a sudden the new GIAC S2 with DSG comes out and some people report problems.
FWIW, my guess is there is an isolated set of extreme IAT/Humidity conditions that didn’t necessarily get replicated in road testing of the GIAC S2 tune w/ DSG tune and it happens to trigger a problem using an open element intake. Either product is probably fine by itself, and in cooler weather. That the one poster mentioned that it flared up when he revved at a stop would lead me to believe it is indeed a heat related issue only present when both the GIAC tune and open element are combined as the air isn’t flowing well when the car isn’t moving.