This is a head on comparison between the A0 size large format inkjet printer.
HP Designjet has bring the gap closer in term of productivity as compared with Canon iPF, but it was compromised with print quality (see video for details).
The new HP Designjet T920 has copy the media output mechanism from toner based multifunction wide format printer, i.e.Oce Plotwave. It is a good idea indeed, but in practical, due to the inkjet printing mechanism and low cost built-up, the functionality and reliability of the HP Designjet T920 top out-put tray is questionable.
As of now, I still think HP Designjet T790 is a better LFP as compare to HP Designjet T920.