Superhuman vs Shortwave

In a show I listened to recently (but not a recent show, I’m a bit behind) @jonobacon reminded us all he uses Superhuman because he wants the Inbox Experience! I recently became aware of https://www.shortwave.com/ which looks like Inbox. So I was wondering if Jono had heard of that and what he thought about it?

I preferred Inbox too, but not enough to pay USD9 per month for the full Shortwave experience or live within the limits of a free Shortwave account.