It's decent enough on the menubar. However, it's absolutely wretched in some weights and size. In particularly in Calendar and the url bar in Safari. Hopefully they can work on hinting and rendering to make it more non-retina friendly by the time of the release, because right now it's as bad as you'd probably imagine.
lol you realize a screenshot won't matter as you're not seeing the pixels on the LCD. That would be like screenshotting your broken iphone screen...
In my opinion, the font kerning is too tight.
In looking at samples of the same text in both Lucida Grande and Helvetica Neue, I find the spacing of Lucida Grande easier to read.
Using a mid 2011 Mac Mini with an HP 2311x (non-retina 1920x1080) monitor.
I personally have had zero problems with font visibility under Yosemite, currently on a 2011 13" MBA. The only slight gripe I have is the WiFi indicator, which is a tad to thin IMO (unsure what it is like on retina), but on standard it is certainly too thin
I have been using beta 1 since day 1. The font absolutely blows. I don't care if you are retina or not. I can never tell if I am connected to wireless by looking at it. Is it black or grey!
I am a fan of thin but something about the font annoys me.