I am always cautious about answering questions rating cookware ranges in a clear list of top to bottom in terms of quality. I have found that each range has its advantages and disadvantages. So for example I always recommend Swiss Diamond to those who want or need a really hard non stick surface because you really can use metal utensils ion Swiss Diamond pans - I do it myself. But for someone who wants a very low fat diet, then the SKK Premium PLUS or the Gastrolux cookware ranges are better. They have a more non stick cooking surface than Swiss Diamond cookware.

But to return to your question of which is better between All Clad Cookware and Demeyere cookware, I would say that they are just about on a par. The top quality shops tend to sell one or the other, rather than both. Personally I would put Mauviel Cookware at the same level as well. But within the Demeyere ranges, there are differences - the top ranges are John Pawson for Demeyere and the Demeyere Atlantis Cookware. Demeyere Apollo comes next. The remaining Demeyere, such as Resto, are lower grade. I am not as familiar with all the different All Clad cookware ranges, but I expect that there are slight differences in grade in this as well. So you need to compare like with like, even within the top brand names.Without more detailed knowledge of the All Clad, I cannot state the precise advantages or disadvantages it may have as compared with Demeyere, but in terms of a general guide, I would say they are on a par.