The "cordwood max" BTU/hr for the King is 57000, and for the Princess is 51000.
Or the "high" number in the brochure for the King is (nearly) 48000 BTU/hr, and for the Princess (nearly) 38000 BTU/hr.
I don't know how the difference between the two plays out in practice, and I note again the 42000 BTU/hr max (no idea how determined) I found for your current stove.
Rather than looking at what others (can) do, I would look at how well your current stove did for your taste, and compare that to the new ones. Homes (insulation, and thus need for BTUs) differ. You do have a datapoint that either worked well or "just barely". Go from there. I'm mentioning this again because of the "barely" and 38 vs 42 kBTU (IF those numbers can be compared and are the ones that should be compared, rather than the 50k+ BTU other numbers...)
@BKVP can tell you in more detail what number you should compare with your current stove.