Hello Bart.
Not to get off topic, but will the Beta RGB workingspace open in Photoshop? Being unwilling to throw away information that can be seen in print (my information is that current inkjet exceeds the gamut of Adobe RGB 1998 for cyan-green midtones and yellow highlights) I  have used ProPhoto in the past and have seen no banding issues. There is also the question of future-proofing current files for tomorrow's technology.
David

To be of value to me, I would need to see a difference in one print in ten. A test for this would be worthwhile doing. And if there is a difference I would expect it to show in prints about 17” wide or more. So not a project I'm going to rush into, but my January holidays would be a good time to try this. So if there is no further post by February, it means I've found no difference.
Interestingly the 6300 is showing up faults in my lenses invisible when the same size prints were done on the Epson 3800. Interesting in the same sense a very bad thing may be interesting. So I think this will be  a good printer to try this out on.

I would be happy to pay extra to get a version of Qimage that printed in 16 bit. Looking at the cost of a large format printer and paper and ink, an extra $20 or $30 becomes a no-brainer. Are there others who think the same?
At present I can print in 16 bit through the Canon photoshop plug-in to the ipf 6300, but I don't get black point compensation. The Adobe Colour Management Module is not available for Windows 64bit. There is not time to go back over my files and re-softproof them and test print with bpc off.
Yes, I've read Mike's article on 16 bit printing. And yes, I'm a purist. (Smiley thingy should go here)