Helvetica has been painstakingly renovated and expanded to make Helvetica Now. In this interview, Charles Nix, the type director at Monotype, speaks about one point which makes this new version considerably better, optical sizing:

…when you see it and you use it, because of the optical sizing, it’s like being reintroduced to an old friend. It’s amazing. I thought I knew Helvetica. I thought I didn’t need Helvetica. And then I see this Helvetica Now and I suddenly realize that’s it not what I thought it was.

Whilst I don’t expect to have much use for it myself, this update is rather fetching.