Hi Fudo,
The Kydex sheaths actually don't
"suck" (don't worry, I didn't take it personally). Rather, they are highly versatile, adjustable and easy with which to work. The tension of the crossguard "lip" can be loosened or tightened to users' preferences.
Here is adjusting instructions for SOG's Kydex sheaths for those who would like to make adjustments to theirs.
Every user wants the drag from their knife during the draw from the sheath to be a bit different, so we can preset it for everyone. Some users, like paratroopers, don't want any chance whatsoever that their knife could dislodge when taking a hard landing, so they want theirs
rock solid and very secure. Other less active people might want theirs to be so loose that they can draw the knife very simply with very little effort using one hand, almost being able to drop it from the sheath if inverted.
So, we leave it up each customer to adjust there sheath exactly where they like it for their purpose.
The coating on the Tsunami, Government Agent, and SEAL Knife 2000 (among others) is a proprietary, highly durable, powder coating (somewhere I heard that similar coatings are based on Teflon technology). As I see it, there are three general purposes for a coating like this:
- Corrosion Resistance: The coating greatly assists keeping the blade as free of rust as possible.
- Low Reflectivity: With its dull dark gray coloring, it is very unlikely that a light source (the moon, a flashlight, etc.) will illuminate the blade. In other words, it's great for covert (or otherwise know as "dark") activities.
- Aesthetics: There are so many knives on the market that do not have blade coatings, rather utilizing more standard blade finishes (such as satin, polished, or beadblasted finishes). Gun bluing has been used for decades. Recently, other coatings from Black Oxide to Titanium Nitride to Boron Carbide have gained much interest. Though these coating do have some practical benefits, mostly, they are added for aesthetic purposes.
TiNi coatings come in nearly limitless colors. Here's a picture of SOG's X-42 Recondo with a "rainbow" TiNi coating:
Hopefully I've answered your questions. If not, either email me or post a question here.