Julian G4ILO has been having some good success on HF with JT9 mode, so I am encouraged to have a go too. This afternoon I'll be firing up on HF, probably 20m.
Results with this mode on MF were very encouraging giving me my first international 2-way QSO (as opposed to WSPR report) some months back. The slower JT9 modes are similar to WSPR in terms of weak signal performance, but allow basic real 2-way QSOs similar to JT65 mode QSOs.
PSK reporter now shows JT9 spots, so it is possible to see where your signal is reaching even if a QSO does not result from a CQ call. The new JT9 Yahoo group is rapidly gaining members and is worth joining if interested in this new mode.
Recommended JT9 mode frequencies are:
JT9 software can be downloaded from http://physics.princeton.edu/pulsar/K1JT/ As updates are still occurring it is best to check the site for later versions regularly. The user guide for all WSJT modes is worth reading.