The cooksets in question are the ones designed for the Svea 123. It turns out there are some significant differences besides the obvious. Immediately obvious is the difference in height, the aluminium set standing about 12.5cm and the steel version less than 11cm. This is because the large aluminium pan is taller than the steel equivalent, the diameters are the same. The volume of the aluminium pan is about 2300ml, the steel 2000ml or 3.5 pints. An odd decision as it means the burner bell of a 123 must be removed in the stainless set, as the stainless pan is not as high and the bell projects too far to allow the lid to be placed securely. If the bell is left on the lid pivots on it. The smaller aluminium pan is also larger but only marginally both being around 1400ml or 2.5 pints. The stove plate and wind shield are identical in size although I prefer the polished finish of the aluminium set to the brushed matt look of the stainless set. Another disappointing difference is the much smaller lip on the bottom of the steel pans for locating them on either the windshield or the other pan. The lip is 3mm on the stainless pans and 7mm on the aluminium pans. This means the steel pans do not seat as securely as the aluminium pans, to the extent that I would hesitate to stack the steel pans. A real shame as this is a great feature of the set in my opinion. So in summary although I consider steel a superior material for pans I think the aluminium set is the better designed and the more practical set.