For the most part, Feedly has been a successful "replacement" for Google Reader for me.
It makes me nervous that Feedly is not as open as Google Reader was, so I'm not really sure I'll be able to recover my subscription lists, etc., down the road.
Feedly rather frequently fails to format articles properly; its most common failure mode is to spray raw HTML across the page, which I assume is some sort of mis-communication about MIME types with the underlying feed it's reading.
Feedly's algorithms for marking articles as "read" when I scroll through them seems to be quite delicate, and often it will re-present articles that I have already read, insisting that I haven't read them yet.
And sometimes Feedly just acts eccentric, for example pulling out an article from 2010 on one of my feeds and showing it to me as "new, 10 hours old".
I'm sticking with Feedly for now, but I'm interested to know whether any of the alternatives are gaining any traction.