For $1000 I get 2 boxes I can't use for anything else right now (and still not very reliable inside my home), whereas with Fastmail (for example) I can get an email service for 20 years @ $50/yr that is very reliable. I'm not sure of the value proposition for this thing.
Why do I need to buy a physical box? Cant they give me a dedicated EC2 Micro instance instead? Solve the ISP issue, and the speed/ connectivity/ power etc?
Down? There's continuity of service if you have a 2nd box online, and it's as easy to restore from a live backup as an iPhone from iCloud.
Email is the first app, and there will be more.