The physical separation between the item you're sharing and the screen element you have to click to share it strikes me as rather counter-intuitive.
My problem with the new Reader is the lack of visual indication of read vs unread items.
Yeah, I had a few people complaining in my twitter timeline and I thought, "Everyone always bitches when something new gets rolled out. It can't be that bad, come on." I logged in and I wasn't impressed but it was he lack of read vs. unread that pushed me over the edge.
Here's the main kicker of that: What's the point of marking the unread count on the left hand sidebar if there's no way to see which ones in the main view? This is what makes me think it's half-baked. They half-removed a feature.
Blogs. Posts.
-------+---------
blog1 | Unread post (b on w)
blog2=>| Old post. (b on g)
Upon close examination, the headline text (not background) for unread is black on white, while the headline for read is very dark grey text on white. The headline for the item being currently read is also black on white.
The contrast is almost unnoticeable (I didn't notice it before), in particular because it's text on a bright background. I'd have to adjust my monitor gamma to make the distinction obvious, at the cost of color reproduction elsewhere. There is more variance in the shades of grey of text on my monitor from viewing angles than there is from this read / unread distinction.
The text varies between #000000 (black) and #222222 (87% black). Good luck distinguishing 87% black text on a white background from 100% black.
https://picasaweb.google.com/lh/photo/RWN8fsl7HjX5SFul8mb7OJ...
So, yeah. The 'read state' of Google Reader is half-baked in expanded view.