We wanted to avoid the Santana Safecase because of the $200 fee for oversize/overweight (which is the same price we usually paid when flying United with a full-sized uncoupled tandem).
Our new Calfee has couplers at either end of the stokers top tube and boom tube (i.e. behind the captain's seat post). It's not a particularly large frame and fits easily in two S&S cases, although we have to remove the front forks. I was trying to avoid that, but so it goes. It took us an hour or two to unpack it and assemble it the first time, but most of that time was spent unwrapping the pieces from their individual padded protectors. One of these days we'll have to try disassembling it and packing it back in the two cases. I am not anticipating any trouble.
We looked seriously at Calfee's clever "wide case", which allows the bike to pack by breaking it into just two pieces, but it violated the 70 lb rule, so we went with the two S&S cases.