Alcohol stoves (Trangia, etc) are great as long as you don't need hot water NOW! They are also excellent for sauteing, etc, especially the Trangia, which has a lid with a sliding top to regulate the flame. There are a number of cooking kits which use the Trangia stove, but are lighter in weight than the Trangia brand models.

Jetboil is tops for heating water fast, and in the ti version, the lightest canister (butane) system. But it's lousy for sauteing, frying, etc. If you need to use one for that, get the Jetboil Minimo, which has a much better regulator than earlier models, also the gadget that allows non-Jetboil pans to be used, and the frying pan of your choice. BTW, the ti Sol, which is being taken off the market I hear, was very easy to ruin. The aluminum version was better at not self destructing, but still really only good for boiling water fast. If all you carrying is meals where you add water and stir, great. Otherwise, no.

cyccomute is correct: as sold, most ti pots and pans are lighter than Al models, but it is very poor conductor of heat, and thus not a good choice for real cooking. Also it's more expensive. Only get it if weight is your primary concern.