The difference is the fins or whatever they’re called. You can see by looking from the base of the heatsink that they are not straight, the edges bend a little towards the corners. This increases the dissipation surface and allows for better performance, at least in theory that is. The base of the heatsink is pretty flat and smooth but it could be better. The first TE had a heat pipe in the core of the heatsink, an empty space inside the aluminum core. This was removed in next versions creating a large controversy among users and reviewers. The Arkua coolers don’t have a heatpipe but they have something similar.