Vesper gets a lot of attention because it's crafted by well-known personalities in the Apple community, namely Brent Simmons, Dave Wiskus, and John Gruber. Part of the reason they're well-known, however, is because they're not only capable of great craft, but of explaining the creative and business processes behind it. That makes it as valuable as them. Cases in point, Brent Simmons technical details on Vesper 007's iOS 7 implementation on Inessential:
You remember in Lord of the Rings when Gollum finally gets the ring and he’s holding it up and dancing around? That’s me and TextKit.
And John Gruber's look ahead on Daring Fireball:
We’re breaking with policy to announce this because sync is so important to so many of you that it was becoming untenable to do otherwise. We want you to know that our priorities align with yours. Sync is the feature that almost everything else on our roadmap hinges upon.
Also: syncing is a notoriously difficult problem to solve. There is no easy way. From the outside, it may seem as simple as “Just use _____”, where the blank is iCloud or Dropbox or Azure or S3 or anything else. From the inside, every option we have presents hurdles, limitations, and a ton of work.
Sync is also important, I'd hazard to guess, because SimpleNote, as part of their return, decided to lift Vesper's design and experience to an appalling degree, making it for all intents and purposes Vesper with sync. And if someone is going to be Vesper with sync, it should be Vesper, with sync.