I use Evernote all day long, every day. It's beyond superlative. It's a requirement for all my employees.
So, that said, work chat is very nice and we use it for almost all of our work discussions, but doing so brings about two recurring frustrations:
Chat is not easily available. Neither as a separate window, nor as an enlargeable list in the sidebar - this adds clicks and time to my workflow every time chat is needed. When I need to find a chat thread, I have to leave whatever note I'm in, clicking "work chat" to see enough of the chats to find the one I need. Then I need to remember and find where I was in notes afterwards.
There is tons of space above my recent chat list to the left in the sidebar. However, this cannot be used to display more chats. One or two is not enough... at all. It doesn't even show the most recent chats as a set number. It seems to only show chats that are actually recent based on a time frame of some sort. Sometimes this is only one chat.
It seems like chat is an afterthought that is not expected to be of much use or value the way it's accessible. It should have a more accessible place, as if it was a separate app, because it is.
Chat has no attatchments. We resort to messaging every time we need to share a photo (or a file that only needs to be viewed once or saved somewhere). This is like the chat in Evernote is actually broken. It's easier to switch apps rather than create a note, attach a photo or file to it, and then share that note as a weird non-visual link in the chat. If you don't need the note afterwards, this also creates clutter.