I’m building a cross bike for Lonnie V. of Spokane WA right now. The frame is steel with swoopy seatstays and S&S couplers. I build quite a few coupler bikes every year in steel and titanium and I love them. The couplers are a beautifully made part that work incredibly well. They add cost and a little weight but they have absolutely zero affect on the ride of the frame. The idea that got Steve S (the maker) to design and start offering couples was that it allows you to pack your complete bike in a case that’s 26x26x10″. That is the max size airlines allow for checked bags without a fee. Since the airlines charge $75 and up for bike boxes it doesn’t take long if you travel a lot to pay for the couplers and case. Another major advantage to the couplers that is largely overlooked is the convenience of getting the bike around. The hard case has wheels and a handle so it can be easily rolled around the airport, but also, unlike the large hard bike cases, S&S cases fit easily in the trunk of a cab. Pricing is a bit spendy at $600 for steel and $900 for titanium plus the hard case $430 and various other accessories that add up to about another $100 but like I said, if you travel a lot they pay for themselves.