I'm looking at stove/fuel sources, and it seems the msr isopro is a pretty popular one. the reviews I'm seeing say the 4oz canister will last a day or 2 for just cooking. Is this the norm? How long does it take to boil/cook a meal? (that's not the dumb question)

The dumb part is I was thinking about packing a couple of those little fuel thingies you see under chaffing dishes at catering events. a 7oz can lasts 3-5 hours (depending how intense you want the flame), which seems like more than enough time to boil water and cook meals for a few days. The whole msr set looks to weigh about 8oz plus the 2-3 cans I would have to carry to get through the week. just bringing 2 7oz (quantity not weight) chafing heaters with a wire contraption I can build myself for a stove top would last me all week would weigh the same or less but take up A LOT less room.

What am I missing? the only thing I can think of is even at high heat flame you won't get enough heat to cook very quickly. has anyone else thought of this, or is it too dumb to even think about?