Welcome to Cheftalk!
When you are shopping for pots and pans, there are a few different factors that you might wish to consider:
- heat conductivity
- durability of handles
In terms of conductivity, Aluminium is excellent, copper is even better but more expensive (such as Mauviel).
You will get a better results from a pan that has a heat-conducting metal not only sandwiched on the bottom, but goes all the way to the sides as well. That's the appeal of All-Clad.
All-Clad is stainless steal with aluminium core going up the sides. But it is very expensive.
Calphalon is usually anodized aluminium, which means that is has a stick resistant surface (outside and inside). Good pan, great conductivity. But it is still an aluminum pan; I prefer stainless steal on the inside.
Pay attention to handles. They should be metal (so that you can slide it in the oven) but still resist heat during normal stove-top cooking. Mauviel and Calphalon tend to become very hot. A handle with an upward curve makes it more comfortable to use. If it points up too much though, it makes it too high for practical use, especially if you are under 6'4". The handle should be solid: 3 rivets helps, but a smooth welded finish on the inside is easier to clean and is more sanitary. Sitram has the best in that respect (Collectivité and Magnum-Pro lines from France).
Weight ensures even heating, no scorching, no warping. However, if you are 80 years old and looking for a frying pan, maybe you need something lighter.
Overall, All-Clad is very good, but there are many companies doing the same concept for cheaper. Sitram being one of them. So look around. I'm always a bit suspicious of "celebrity" cookware lines. You pay for the name; I'd rather pay for actual quality.
I hope this gives you enough info to ask the right questions.