I have a few thoughts to contribute to this.
Here is a quick cell pic of my three user Opinel folding knives.
Opinel Raw Walnut:
My friend Sam (Avoidspam) graciously gifted this to me. I did a fair amount of mods and finished the wood with a hot one week soak in Raw linseed oil. One month cure time in ideal conditions and this walnut is stunning in person. Love this knife and left the lock. The stainless takes a wicked edge and holds it.
Opinel 1890 Cherry:
This was a gift for a job. I slowly modded it while using it daily. The cherry is soft and soaks up anything that touches it. Linseed oil was NOT cutting it. I took about 3 weeks to do a Danish Oil finish final coat of renwax buffed off with a dry/clean wheel. Lots of mods on this one including stag blade stop. 1.22 ounces my favorite to carry. After all the finishing work its now VERY tough and weatherproof.
Opinel Ebony:
This came with a mirror polished stainless blade. I knew refinishing would be a lot of stock removal judging by the buffed out nail nick and logos. I did a blade swap and then noticed how wavy the grinds were on the blade. Fine on the rustic 1890 but not so much on the refined Ebony. I reground the blade from spine to apex and gave it a microbevel on my stones. Cork belt finish 600 grit. This also has everything refinished, stag blade stop and crocus cloth finished collar.
Summary:
They are all great and to give my 2cents on the steels I found differences. The carbon IS softer but I did side by side cutting tests on cardboard, wood and whittling. Cardboard side by side they both still slices newsprint after a lot of cuts. I could not pick up on much difference and they both still shaved. Slicing green woods neither dulled. Whittling green woods neither deformed or chipped.
As for carbon being weaker I don't think so. I think this may be due to MICRO burrs from over sharpening. I say this after making SURE my two had NO burrs and doing my cutting tests.
I found it was easier to form a burr by accident on the carbon due to the softer steel, but once the edge was properly finished it has been STRONG. The stainless sharpens easier in my mind. Anyhow, just some insights from my usage. Take it for what its worth to your day to day.
Kevin