Those who have been on this forum for a long time know I've done a LOT of experimenting with stoves, etc.

Looks like all the essential information has been covered in the other posts on this thread. It's worth repeating that Esbit is NOT Hexamine, which is very toxic, has toxic fumes and residue, DOES deteriorate dramatically with age, and should never be used indoors (if anywhere).

A year or so ago during Isobel I ended up making a hobo stove out of a coffee can to use Sterno to boil water when the power went out. That was so ineffective that I've since bought 3 of the Esbit stoves, one of which lives in a kitchen drawer. There's this awkward period after the lights go out, and you have no idea how long it's going to be, and don't know if it's worth breaking out the heavier gear (I have a kerosene (Alpaca) cookstove that works like a space heater and is usable indoors). If the power goes out in the evening or at night, the awkward period probably includes the morning coffee/tea time... and you might even be going to work that day, power or no, which also argues against taking the time to break out "serious" gear. The Esbit works very well for this in-between stage, when you're not yet committed to the long haul. I've also sent them to family members for blackout use.

Backpacking and hiking I usually carry one of the little Pepsi-can stoves these days- can't beat it for weight- but I do keep Esbits in various kits. Can't beat the Esbits for convenience.

I think you'd be surprised at the shelf life. As kids we used to use these things to power model steam engines, and I never remember any deteriorating, even when I used them 10 years later. I use them occasionallly now to power model Stirling engines for demo purposes. Having something that's (relatively) safe to use indoors can be a real advantage.

They are, however, as you noted, very sensitive to even a slight breeze. It's well worthwhile to take the effort to shield the stove well.