...on the other hand, the PB360 will display the RTFs nicely as is, with no effort required.
Still, if you have the time to convert to epub (calibre can do the honors well enough) and you use the updated FBReader, you *will* get a nicer presentation with proper chapter breaks.
Just make sure to keep the rtfs handy.
History has shown that a lot of "eternal" standards turn out to have shorter lives.
Rtfs, however, are likely to join cockroaches at the end of time.