I will add two comments to the previous message that migh be seen as reasons to prefer a regular Pt/Pd. print over a Pt/Pd toned kallitype. .
Originally Posted by philsweeney
1. In toning kallitype images with palladium I have found that it is possible to replace or convert something on the order of 97 - 99.5% of the silver to palladium, but not 100% of it. I suspect that the small difference in silver remaining in the toned kallitype would be a much less important factor in archival qualities than how the print is processed, type of paper support, and storage conditions but in the absence of actual samples there is really no way to know.
2. Persons involved in promoting and selling their work in galleries, etc. would probably do best to stick to Pt./Pd. Although as photographers we may believe that that process matters less than the image, in the marketplace process matters a lot. For a variety of reasons Pt./Pd. prints will attract more attention, and sell better, than Pt./Pd. toned kallitype, all other things being equal.