I'm seriously thinking of switching to a gel fuel. Its properties are a good hybrid of alcohol and hexamine. It ignites with a spark, like alcohol, but has less spill danger than alcohol. To burn it you need a shallow container to hold it in place, which is almost as simple and compact as hexamine (which just needs a platform). The same burner could be used for both solid and gel.

Hexamine fuel is easier to carry. Gel is similar to alcohol: you can keep a small amount in the burner (which has a tight lid), and any more needs to be in a bottle.

I've seen reviews which say it is slow to boil, but in my first test it was faster than alcohol. Maybe it depends on the stove. I was testing Trangia versus Trangia and the gel seemed to burn over all its surface where the alcohol only burned in a ring. Both burners were with Trangia's stove.

There's no simmer. It's OK for boiling water for drinks, and heating up pre-cooked food, but probably not for much actual cooking.

I'd be interested in other people's opinions. I've seen mixed reviews. Some people hate it, others get on fine. My intended use is single-night camping (although my camping kit is now small and light enough to live in my car boot as a get home bag). I would not expect to cook for three during a power cut with this; that seems a lot more ambitious to me.