It depends what you're planning to do with the knife, I have a Svord Peasant and several Opinels but haven't tried the K55k. Given the choice between the Opinel and Svord I would go for the Opinel, here's why;
You can pick a size which you'll be comfortable with, the Svord comes in one size and I find it an uncomfortable knife to pocket carry.
The blade on an Opinel is more versatile in my opinion (I expect someone'll chime in and say the opposite

) with an acute tip, some belly and a sufficient flat portion close to the handle for wood working. The blade on an Opinel is very slightly convex giving what is fairly thin blade stock a fair degree of strength. When sharp the Opi out slices everything else I have. However, if you're planning to 'beat' your knife as some like to say, then the Opinel isn't for you. This is a cutting tool

The Opinel is a very comfortable light knife to use. Despite having a round handle the weight means you soon forget it is in your pocket.
The locking mechanism is probably the most divisive part of the Opinel, some hate it, i personally get on with it fine.
I purchased a Svord Peasant because i was fascinated by its simple friction method (basically, you can adjust the front and back screws to pinch the blade both when the knife is open and shut). I still love this idea and it's nice to see in the flesh.
The Opinel will be a shade easier to keep sharp (you'll have to sharpen the tip as they come with a blunt tip).
Choice of good quality carbon and stainless on most models.
I'm sure you'll like whichever you choose, plenty of info on these knives on this and other forums. Respect to you for gathering as much info together before making a decision
Sam