My Epson P600 stopped working and I have just replaced it with a Canon PRO-300. The first print I tried on the Canon was directly from PL4, the way I have been printing for ages. But when the print emerged, though the colours were pefect, the image was highly pixellated - maybe 2 or 3 pixels per mm. It is as though PL sent a low-resolution image to the printer. It was an uncropped 20 megapixel image and I was printing to A3, so there should have been plenty of resolution. The workaround was to export to a full-size TIFF and then print that with the Canon printer utility, which worked perfectly.
I cannot work out what settings could have been wrong. Does anyone have any ideas?