The weight works great on a high DPI display, but on older displays, it just doesn't work. Open on a rMBP or iPad, and it's beautiful. I'm guessing the designers are working on a high DPI Mac.

Edit: should be sorted.

Original: working on a standard DPI Mac, but it still looks fine - see http://imgur.com/WRWYzBx. Trying to figure it out now...

Do you mean "fine" as in "very fine lines", or "looks fine" as in "looks good"?

Cause that looks like a printer that ran out of ink.

I'm guessing OS X's font smoothing is more aggressive and makes it look better than Windows'. It also depends on how the font was hinted for Windows, whereas on OS X, the system "knows best" and has its own font smoothing technique.

I am on a rMBP and I wouldn't call it beautiful.

It's painfully thin, and the eyestrain factor is pretty high.

I downloaded all of Google’s font library and installed it locally, means I can read the fonts without having to load them from Google. Still doesn’t help against fonts with 0.5px thin lines.

Back in the day, running a massive library of fonts slowed down many apps. Is this still the case? I'm running Mac OS X 10.10.

I’m on linux, and yes, it does. Opening the font selection menu can take for me, with 7000 installed fonts, about half an hour sometimes. I just don’t do that, instead select fonts by name (I know most of them now).

But you don’t notice it until you open a font selection menu.

That's insane! Guessing you don't use Photoshop. At least, the last version I used (I think CS5), the font selection was weird and, no matter what, required that you open the drop down. Bleh. Haha

Photoshop on linux, that’s funny ;P

But seriously, I had to use Gtk3's font selection menu today, and it was impossible to work with it.

Also on Ubuntu. I (only) have 671 fonts, no delay at all for me.