I asked a very-experienced rando friend (who has a Bike Friday that he's ridden on a 600K) what bike I should buy for a travel bike for PBP. He advised me to get an S&S-coupled regular bike, rather than a BF. The reason is that the smaller wheels on the Friday are stiffer and transmit more road shock, thus causing fatigue.

The Ritchey Breakaway looks like a great alternative to S&S, but while the latter has stood the test of time, I don't know that the Breakaway has been around long enough to know its long-term durability.

Anyway ... while my S&S coupled bike is great to ride, it is definitely not a "no-brainer" whether to take it on a trip. It is quite a bit of work to disassemble, pack, unpack, reassemble (and then repeat at the end of the trip). I'm pretty fast, but it is probably still at least an hour at each end. The Ritchey looks like it'd be about the same. A Bike Friday would be faster and closer to a no-brainer to take with you.