I have the Thermette and Kelly Kettle but haven't used them so can't attest to which one functions better. They both certainly appear well-constructed and capable of doing the job they are advertised for. I recall reading that the Eydon is higher quality. And my extensive research advised that any of the three would be a great addition to my gear.

The principal difference between the Thermette and the Kelly may be which is easier to pour with less risk of being burned. The Thermette's handle is spartan and puts your knuckles at risk. The Kelly requires two hands to pour.

The Thermette was on backorder last spring so took longer to get here but that inventory situation may be resolved. Kelly's customer service was superb as they were responsive to e-mails.

The Kelly is in my teardrop trailer (which is in storage near the mountains) because the one I got is a bit more compact than the Thermette.

I got the Thermette because its copper and it has a history that appealed to me.

I ended up with two because my teardrop is near where we camp and I didn't want to lug a kettle back and forth from the city.

They are not compact.

As survival gear, any of these kettles seems like a wise investment. Gotta love a stove that will run on twigs or dung.

If my JetBoil weren't so efficient I'd have used the kettles by now.

Need to take the time to play with them.