The Cube Dovetails are really quite different from the earlier dovetails, the latter which all came rectangular shaped in just two colours, raw aluminium and anodised green (light or dark green depending on which batch your puzzle came from). In the numbered set, the colour combos are dark green/blue, orange/blue and purple/blue, the same blue that is found on his First Box puzzle. While this departure from the traditional raw aluminium/green combination from the earlier models is a welcome change, I wish he had a yellow/blue cube or even a raw aluminium/blue or some other better contrasting colours than dark green/blue. I actually asked Wil if he had other colours but he said "sorry no".
Solving the cubes is pretty easy if you have had prior experience with the earlier dovetails but each of the cubes dis-assemble (separate) quite differently. Once apart, you can see the precision milling/cutting that has gone into making them look impossible to separate...really quite amazing. As an aside here, veteran puzzle collector Michael Tanoff had remarked to me that the "puzzle" associated (with the dovetail puzzles) is not how to separate the parts, but rather to try figure-out how the two parts fit together, as all three appear to be impossible objects...".
If you already own the earlier Dovetails, well...this set is certainly a colourful and fun must-have; and would enhance your collection. If you don't wish to buy all three, Wil does sell the cubes individually. Allard has also written about the cubes in his puzzle blog so you may wish to check out his thoughts on them.