I had asked my Dutch friend JD to write a review of the Spyderco Air. He’s a big fan of small blades. From the classic slipoint to the most modern design, he’s always seeking for the best geometry in cutting. Through the years he has developped an wide encyclopedic knowledge in cutlery but also has proven to be the best free hand sharpener I have ever met, being able to enhance any edge to a very high level of pure performance. Here is his review of the Spyderco Air:

I have had the Air in my possession for 4 months of which I have carried it for about two. When I first got it I liked the knife overall but thought it was too thick behind the edge and found blade finish a little rough. Since then I have thinned out the shoulder of the edge, so now the blade flows from the back to the edge in a slightly convex curve. The first halve centimeter from the edge is now just a little thicker than on an Opinel in the same area. I consider the blade grind on Opinels to be a benchmark of a thin, very well cutting, folder blade. I used an extra course DMT diamond stone for most of the shaping. It was then cleaned up with sandpaper. The edge was finished on an extra fine DMT stone. It how has a fine jet toothy edge that will easily cut phonebook paper, shave arm hair, as well as be grabby enough to bite into and cut plastic packaging material.
I tried sharpening it with the brown Spyderco ceramic hone. A hone that I have good experiences with sharpening other (Spyderco) knives. But found that for this knife it was not the right tool for the job. It polished more than it ground and so was right for the shaping part of sharpening. The M4 steel the blade is made of is quite wear resistant compared to, for instance, VG10, a steel Spyderco uses in many of its popular models. M4 is not stainless.
I use the Air to cut up an apple in the evening, to cut a piece of cheese or to get liverwurst from its plastic packaging. It also works well for opening up a kaiser roll and putting butter on it for lunch (butter with the back of the blade). It work great for the usual edc tasks of opening packages and cutting paper. With use, mostly thanks to the apples, it has developed a nice dark patina.

The handle feels good in the hand. No sharp points and, thank goodness, no jimping! Only when you push hard on it does the open construction become a little uncomfortable.
The Air opens and closes smoothly. The linerlock on my example has moved a little past the middle of the locking ramp. Slightly further then when new.

The detent is strong enough to keep the knife savely closed in the pocket.
In the pocket you hardly notice it, it is so light and compact. I have not missed a pocket clip at all! I think on this knife a clip would compromise the ergonomics of the handle to much.
The more I carry this knife the more I enjoy it. Thinning behind the edge make all the difference! It has transformed the knife from okay to a great cutter.
JD