I wouldn't agree that subbing SDHC for SxS is a minefield nor is a Panasonic SDHC card any less reliable than any other brand. SxS is just a memory card format and unlike certain other formats is not particularly proprietary nor high performance. Used properly, SDHC is a perfectly viable and inexpensive alternative.
Current firmware for EX cameras is very SDHC friendly . . . which is why Sony was finally willing to make an adaptor. Certainly there are some cards that a better than others but that just takes a little smart shopping. In the good 'ol days some tape stock was better than others too.
SxS offers better transfer times but it has major downsides IMHO. Being able to buy more cards, which you can with SDHC due to the major price difference, means you can avoid offloading during shoots where human error is the biggest factor in failure. If you have to, it's much easier to hand a client an SDHC card and give them a "stock" charge. It's much easier to find a device to transfer SDHC as some computers have built in SD slots and card readers are widely available and inexpensive. Past issues with SDHC was due to Sony's firmware and not necessarily the cards themselves. MANY cameras now use SDHC cards.
By minefield I did not mean it is a bad idea. I have been using them myself since 2008 without any problems. It was Craig's findings that helped me decide the route to go (old Sandisk/Transcend 16gb/MxR). My comment was really based on seeing so many posts talking about failures with combinations of cards that are not up to it.