I would appreciate advice about which cases to purchase for my Calfee carbon Tetra Tetra with S&S couplers. I have been told that it is safest to buy the hard cases, and have also been told that the semi-soft cases are fine (not the backpack types). The semi-soft are cheaper, but that is not a criteria given the cost of repairing it if it was to be damaged.
We also heard the comment that the semi soft cases are safer because airport personel treat them a little better than they treat the hard cases.... We have one hard case one, not the S&S, for the wheels and one semi soft one for the frame pieces, also not an S&S. Our cabrio frame would not fit inside the 26x26x10 S&S case.
I purchased the two S&S hard cases when I had our '02 Erickson S&S tandem built... and promptly sold them. I replaced them with a different hard case from Parker Plastics (same company that probably was sourced for S&S' cases) and a backpack case: no regrets.
However, I do the opposite of cornucopia72 and use the soft case for my wheels, saddles/seatposts, a clear plastic tackle box containing the cranks, another clear plastic tackle box containing the cassette / axles from my Phil Wood hubs (allows the wheels to pack very flat), chains, and tools needed for disassembly / reassembly. The hardcase is used to protect the high-value / harder to replace frame pieces, fork, and handlebars. I had originally included the drive train parts as well as the saddles/seat posts in the hardcase before they lowered the max weight for checked baggage from 75lbs to 50lbs. The lower weight limits necessitated redistribution of the parts to the current packing solution.
My issues with the two hard case solution offered by S&S and their dealers back in '02 -- noting that they have since added two additional case options to their product line -- was the awkward handle / wheel placement on each case and the inherent need to have two hands / people tied up to move the cases around. S&S has since started to offer a couple different cases, including one that is very similar to the case I purchased with pull-behind handle and reinforcing ribs.
Rather that wasting bandwidth here, let me just refer you to my Web page on packing and travelling with our S&S tandem. My rationale for going to the Parker hard case / S&S softcase solution is outlined in the Green text box entitled: Why On Earth Did I Sell Both My S&S Hardshell Cases?