The comments from Larry, VA3LK echo my thoughts to a large extent. I feel
that, FOR CERTAIN SITUATIONS e.g. transatlantic attempts, BPSK as
implemented in Coherent/Africa is specifically designed for the job and
would probably stand a better chance of success than, say, PSKxx or QRSS,
given adequate phase stability of the propagation path. It certainly seems
to have been used with success in the USA, with Part 15 LowFER beacons (<1mW
ERP?) apparently producing reliable copy over paths of 1600km+ under the
right conditions.

Having said this, I believe the US LowFER distance record may still be
USA-Hawaii using standard CW! It is, indeed, very much a case of "horses for
courses" and I certainly wouldn't make a blanket claim that any one mode is
superior to any others. Basically, like everything in this hobby, it comes
down to using whatever you are comfortable with and/or have the kit for.

Lastly, and with reference to recent comments on the reflector, perhaps a
more correct term than "machine modes" would be "machine-assisted modes"!

Regards

Kevin, G1HDQ