Thin weight type has uses in good design, but the way it's being applied ad nauseum today is a gimmick.
Thin weight type has uses in good design, but the way it's being applied ad nauseum today is a gimmick.
The overuse of thin fonts might look dated in the future, but I don't agree that this trend is totally inspired by retina screens. If anything, I think Serif fonts have seen the greatest resurgence on web due to Retina screens. High DPI screens will impact our perception of all fonts, just as sans serif grew in popularity on lower dpi screens causing their perception to be more modern and technological.
In general typography as a whole has become much more interesting on retina screens. So yes, fonts look better now than ever before so don't cheat by using superthin because its trendy.
San Francisco seems to work best at (very) small sizes, where Helvetica breaks. It proves further that Apple thinks of each screen size as a distinct UI - clearly the biggest difference with Google's approach to UI. Off topic: the 2 screen sizes for Watch show they don't want accidental developers for this platform, only fully committed ones.
I do find Helvetica works better on my Mac screen than SF (I tested in Mail.app).