Unless you do a lot of airplane travel* I'd stick with what sounds like an already excellent bicycle collection. If you do travel by plane a lot, I think the BF configuration with the trail-able suitcase is easily the most hassle-free option since you can assemble it and ride off right from the destination airport in minutes, although someone here (I forget who) did some sort of S&S setup with a bag/soft box that juuust fits the thing, and that looked very compelling. My NWT is a nice little machine, surprisingly hardy, a perfect fit, and it has taken me to some very neat places, but it sits all folded up in its Samsonite case 99% of the time.

*Caveat: There is another purpose for the BF/suitcase bit, but I've never made use of it. I corresponded with a fellow from South America briefly who had a portable/deconstructable kayak, which he would store in the suitcase while he was riding. If he reached a river he wanted to row on, he would do a sort of leap frog routine between bicycling and kayaking - unpack boat, pack bike and store on boat; unpack bike, pack boat and store on bike, etc, representing a neat self-contained amphibious transportation motif.