I purchased the No. 7 with the 3.15" (8cm) blade. I'm assuming the larger and smaller carbon steel Opinel knives are similar except for the size. This is an interesting design. The stainless steel "Virobloc" safety ring locks the blade in the open as well as the closed position. There is a nail cut in the blade to assist in opening it. The handle is made of solid beechwood and is nicely carved and finished. It serves as the frame and the handle. The only reason I didn't give this knife five stars is that it's very light weight. The blade has a full grind and is very sharp, but it's only 2 mm thick. It will undoubtedly cut and slice very well, but it weighs only 1.6 oz. Far from as robust as a good fixed blade knife, at $14 this Opinel folding knife is a remarkable value. At first look the Opinel appears like a relic from a past century which makes the knife very appealing. I like this knife and plan to buy a few more.

There are a number of thinks to like about this knife: The blade is extremely sharp right out of the box; it is very easy to sharpen; the handle feels well-made and the locking mechanism is effective, if not user-friendly. But, there's one significant drawback: the knife blade is very thin. Much thinner than any other pocket knife I've seen. I'm more than a little concerned that it won't hold up to heavier duties like whittling and sharpening sticks. If your uses are no more demanding than cutting packaging tape, it should be fine. But, if you're going to use it for hunting or camping, I have my concerns..

I really like this Opinel No.7. It's great cheap knife. I like high Carbon steel because it holds an edge very well, are durable, and I like playing with knives. My knife didn't come hair shaving sharp from the factory. The design of this knife lends to a very sharp blade. It's an old-time friction folder or peasant knife and, if you like that style of knife, it's very cool. I like this type of knife. It's not aggressive looking and it has a lot of history in it. These are knives that you hand down to your kids or grandkids.
The reviews state differently, but this isn't the knife I would use everyday on a job site. I would use my Morakniv. The beefier blade and Scandi grind are better suited for work in my opinion. The Opinel is a great knife for EDC for cutting boxes, apples, packages, etc., but I wouldn't want to beat on it too much. It's more of a scalpel than a bush knife. It is an old design that is mounted on a wooden handle; I'm sure that it would break down quicker than a knife in a metal frame.
Don't misunderstand me, I really like Opinel knives. It has a lot of history and a tremendous blade. It's a super value for the price and would rather carry this than any Chinese knife with an inferior steel. Some of these reviews are over-the-top for a friction folder with a wooden handle. It's great for what it is and, if you take care of it, it will be a great knife for decades.

I've carried pocket knives for 50 years. This is the best non multitool/swiss I've ever owned. If you've already decided you can get by with a single blade pocket knife I don't think you can beat it.
I bought the no 6 a few months ago. So far it's cut rope and packages, opened mail, enlarged the latch opening on a doorframe, cut/scraped old epoxy off boards during a window repair, sliced apples and oranges for my lunch, served as a drawknife to alter a new ax handle, cut up cardboard for recycling and dispatched & gutted a dinner-size bluegill.
PROS
Takes an amazing edge the thin blade and good carbon steel can't be beat for ease of sharpening.
Fits my hand beatifully. I was convinced the flared fishtail end would bother me. I was wrong it's comfortable with any kind of grip.
Back of the blade is a good scraper.
Extremely nimble and a wonderful slicer.
Cheap.
Amazingly lightweight - carries extremely well.
CONS
Two hands to open.
Not meant for batoning wood, digging holes, turning screws or prying - but cheap to replace if you beat it up too bad.

Useful and even elegant edc. A pleasure to use.

Obviously some people (myself included) love this knife party for its old-fashioned design. But let's face it: These knives would never be as popular as they are if it weren't for the price. Modern features, such as automatic blade locking, blades that open with a positive "snap," etc., make this knife's design seem decidedly outdated in comparison.

However, those modern added features come at a cost. If you're after a quality, VERY sharp blade for low cost, this is simply the best deal you'll get (or at least the best I could find).

Here's what I love about the knife:

* The blade is extremely sharp. It wouldn't shave hair off my arm like my Mora Companion did out of the box, but somehow it actually seems sharper when it comes to actually cutting. It sliced a tomato with just the slightest (less than a 1/16th of an inch) sawing motion to cut the skin. Pruning small branches is like cutting butter. It sharpened a stick with unbelievable ease and smoothness. The blade feels and acts thinner than it actually is (meaning it is stronger than it looks), probably because the entire width of the blade is beveled at apparently the same angle, from the spine right down to the edge.

* The whole knife is very lightweight and sleek in the pocket. I don't even know it's there.

* The locking mechanism works better and easier than I expected from the photos. It locks the blade both open and closed, and although it has to be done manually, it's easy to twist the collar. It holds the blade open or closed plenty effectively for anything such a knife ought to be used for.

* The look and feel is cool. The wood handle has a nice feel and is comfortable to use. The blade is nicely machined and looks well-finished.

* Did I mention it's SHARP?

With all that said, there are some things I find less appealing:

* The all-wood handle makes me hesitant to use the knife for some tougher things that I assume the blade could handle. Maybe it's just me, but I don't have enough confidence in how the blade attaches to the handle to use it for mcuh more than "normal" slicing tasks.

* The blade has absolutely no "snap" to it when opening or closing - not even equivalent to an old penknife. It's just a blade on a swivel, and therefore lacks any tactile positivity when opening or closing the knife.

* Although the locking mechanism surprised me at its effectiveness, it's only effective if you remember to do it. Although it will doubtlessly become habit with time, I still prefer an automatic lock.

It should go without saying that those nitpicks completely disappear when one considers the cost of this knife. Sure, I could (and hopefully someday will) get a $45 Buck pocketknife that will have the modern features I like with a quality blade. But until then, I'm confident that this knife will excel at anything a non-tactical pocketknife should ever be asked to do.

Bottom line: If you're after a sharp, quality blade on a budget, this is your buy.