As many have stated, they are both excellent knives and serve different roles. I always keep an Opinel #4 in my pocket. It weighs exactly 1/3oz. My little house key, with 1" keyring weighs more. Now, my stainless #6 is the smallest Opinel with a lockring. However, it weighs a full ounce. It's kind of bulky in the front pocket of a pair of jeans. Still, it gets so sharp, holds that sharpness well due to the quality steel and thinness of the blade, that I use it more than any other knife. It sharpens as easily as my #4 in carbon steel. Tonight, I used it to shave down the quills of turkey feathers while making fletching. Opinels might be the ultimate slicers. I recommend them in stainless over carbon. Never thought I'd say that. I too use a SAK Hiker. It has all the tools of the Farmer and more. I also use the Fireman, Florist and Hunter XT. The Opinel #6 is a better gardening knife that the SAK Florist. However, I'm constantly needing one tool or another found on my SAKs. Tonight, I needed a pin. I grabbed my Hiker and pulled out the pin I had purchased aftermarket and got the job done. Yesterday, I grabbed the Fireman and unscrewed the tiny screwdriver from the corkscrew and used it to open a battery compartment on a bicycle light. This evening, I used the saw on my Hunter XT to clear a shooting lane while out bowhunting. Those are things you can't really do with an Opinel.
Joe