Here is my humble opinion about this:

If the portable recorders are to be used eventually to transfer work to PC for final editing-what is really needed for professional result, it would be nice if they could provide the capability to write to external firewire harddrives so that these harddrives are detached from the recorders and attached directly to the PC. Then the file transfer will make sense.

In fact, if I can find such a recorder, it will absolutely make lot of sense of portability. So they will be used in live settings to capture the live recording in multiple tracks. Then the tracks are easily tranferred to the PC by simply disconnecting the firewire harddrive and connecting to the PC and BOOM you are ready.

But to transfer each track one by one and to force it to go to D/A conversion then back to A/D and to pass through the whole gain structure, seems to be pointless and defies the purpose of portability and ease of use.

Harddisk recorders are created in the first place to allow some users to avoid the PC altogether. It does make sense for those who do no care about the advantages that the PC gives them and they truly want to avoid the hassle of building, learning, configuring and maintaining and paying for a professional DAW.