In reply to richprideaux:
Yeah, I think the Helios is no longer sold. You can kind of simmer, but it’s difficult with stoves with a pre-heat coil, turn it down too much, and you get a delay before it splutters and turns off.
I bought it to address 2 issues I’d had with Jetboil and Reactors at altitude: lack of stability, leading to a few spills with the clumsiness of cold and altitude, and the gas cyclinder melting down into snow/ice and getting progressively less efficient. It is much better on both these issues.