"It says its the smallest canister stove in the world weighing only 1.5 oz"
It's not just the size/weight of the stove itself, but IMO best compare the overall cooking 'system'. Pot, windscreen, fuel bottle/canister, fuel type and associated efficiency, and ancillary stuff like matches/lighter, perhaps a fuel measuring cup for alcohol stoves, maybe a cozy ... the works. More complicated yet is to factor in how much you'll use the stove --- typically in terms of how many cups of water you'll heat (maybe or maybe not 'boil').
It's not easy to compare different types of stoves in terms of weight in a truly apples-to-apples basis, especially when you consider not just iso-butane and alcohol stoves, but others like esbit (solid fuel), wood/twig-burning stoves, white gas ...
My favorite stove is typically no stove --- and thus no pot, windscreen, stove, fuel container (or fuel).
I own these stoves and use different choices for different applications:
(1) some sort of generic snow peak canister stove (pizo-electric lighter broke so I removed it to save weight)
(2) kovea spider for mild winter use
(3) various alcohol stoves, typically now a 12-10 stove that came with my Caldera UL Compact system.
The Caldera UL Compact is a caldera cone variant that isn't sold anymore, dunno why as I like mine --- pretty efficient, packs very small, everything fits in the 850 ml pot. http://www.guthookhikes.com/2011/10/caldera-cone-ul-compact-alcohol-stove.html