Rating: 4 / 5
I've been carrying the Optimus Crux since 2001 as a lightweight alternative to my Dragonfly. Due to its ease of use and weight savings, the Crux has been my stove of choice.
It is lightweight, compact, simple to assemble, simple to use, and works every time with no maintenance. Wear and tear after 8 years of sometimes heavy use is limited to the pot supports bending out of alignment in recent years. (Easily fixed)
Over the years I have two consistent concerns/complaints; neither of which have motivated me strongly enough to make the change to another stove but warrant a 4 rather than 5.
The first is pot stability. The three-prong design makes it necessary to take particular care with the placement of my 2001 MSR Titan Kettle. The spaces between the supports are large enough that if the pot isn't centered it becomes unstable and can fall or slip off with a bump. Knowledge of this problem and a little care generally mitigates the issue, but a careless moment could easily result in an accident. This is not an issue with a larger based pot. Brunton's new version of the Crux, the Flex, has a 4 support design which I'm sure eliminates this issue.
The second is undoubtedly true of all non-piezo canister style stoves. I just find the lighting to be a bit awkward especially in windy situations; as you need to hold the canister stove while turning the knob and somehow applying flame. I always feel like I need a 3rd hand, but again, I always get it started.
The stove's simmer capabilities and fuel efficiency are excellent!