I use Cape every day on my iPhone. The service is excellent, and the security features haven't ever interfered with my use of the phone. They have a convenient mobile app for setting up extra features like the IMSI rotation and getting support. As a tech savvy user, it matches what I want.
I'm a target for a variety of things, and knowing that no one can SIM swap me is worth the subscription alone. The SS7 protections, encrypted voicemail, secondary numbers, IMSI rotation, etc are all a bonus.
I have a conflict of interest here (I am an advisor to Cape, also a security expert, and my company has done security audits for Cape), you should absolutely look more deeply into what Cape has created. Their service is fundamentally different than other "security-focused cell providers" (mostly snake oil IMHO) because Cape wrote their own mobile core, nearly from scratch. They control the whole software stack and have done really innovative things with it.
Here are a few things you might want to look at more closely:
We're a bit non-committal about who this affects in the blog, but phew man, there are a lot of agent systems that will fall victim to this general class of attack.
This is cool, and I'm glad to see someone doing this, but I also feel obligated to mention that you can also just quickly deploy your own VPN server that only you have access to with AlgoVPN: https://github.com/trailofbits/algo
I'm a target for a variety of things, and knowing that no one can SIM swap me is worth the subscription alone. The SS7 protections, encrypted voicemail, secondary numbers, IMSI rotation, etc are all a bonus.