I don’t own one.
It’s interesting, and admirable, the concept of a “modular” phone where parts can be readily swapped by the end user.
I’m not convinced it’s something that will take off. They’re not exactly cheap, which for me would make it a really viable alternative that can end up in the hands of lots of people. I like the idea of a phone that lasts but I’m not sure that should be their selling point. Plenty of phones can physically last the 5+ years they’re talking of. My last iphone (a 4s) lasted at least that long - until I gave it to my girlfriend who promptly destroyed it in less than 3 weeks!
If you don’t need to play the OS obsolescence game a phone/computer or any piece of technology can last plenty long enough. Human desire for new and shiny is a harder thing to overcome.
For me it would be better to spend the time and effort learning how to fix and repurpose the things I currently own than buy into this.
As a slight aside, reading about this phone made me think about technology, obsolescence and fixing stuff which, in turn, reminded me of a video I saw recently on youtube. Cubans have the right idea 
