I would actually rate the Covert much higher than the Avalanche myself. It has been one of my favorite knives since its introduction. The production quality is excellent on the Covert. The single ground Covert is a surprisingly good utility blade. It has a full-width flat grind on it that is excellent. The straight blade with the narrow tip makes it excellent for any chore from paring to self-defense. It is a strong, versatile, and efficient cutting tool. I would not bother with the double ground version.
The Covert is ambidextrous, the Avalanche is not. The Covert comes with the LAWKs safety, the Avalanch is a run of the mill liner lock. The SpeedSafe mechanism with a thumb stud, as opposed to a "flipper" is actually more of a liability than a benefit in my experience. You have to relearn your opening motion with your thumb, or the result can be a cut. You wind up flicking the Avalanch to start the assisted opening then having to raise your thumb out of the way to keep it from catching up to the blade edge. The same motion would result in a flicked open blade on a liner lock folder without the assistend opening, so the assisted opening is effectively wasted in my opinion.
The Avalanche does have good ergonomics, good steel, and a good initial cutting edge though. The Covert is still my favorite of the two by a wide margin.