> The major con is you have to trust that they are using a secure system.

From my discussion with the founder on that HackerNews thread yesterday (and his other comments on the thread), it seemed clear that they didn't have a good enough understanding of the space - both the technical security requirements and the existing solutions. If you're not clear on what problem you're trying to solve, I doubt that you understand the domain well enough to solve it properly - at least when it comes to security.

Security is one field where 80% of the way isn't "good enough" - in fact, 80% may be worse than nothing at all.