Last week when I did my hammocking trip on the FT another thing I did was carry my esbit gram cracker stove and caldera cone and a "popular alcohol stove" so I could compare them.
There was no wind but I still used a windscreen and the alcohol stove took 2 oz's of alcohol and around 9 minutes to boil 2 cups of water.
The esbit/caldera combo boiled 2 cups of water in just a little over 4 minutes.
Granted, the caldera cone setup is pretty efficient but as that was my first experience with alcohol it'll probably be my last. Too slow and uses too much fuel.