I have been testing the new version in Chrome and it looks amazing. Thank you so much for putting your efforts on renewing the web client (I was waiting for it for long time!). Here is some feedback I've collected for you to continue with the improvement tasks.
In the last days I have been experiencing some spontaneous logouts. In such cases, while I am working on a note, the page refreshes itself and a message appears saying that Evernote was not able to load (see attached picture). Since I am accessing from Finland, I think it could be the case that you are doing some nightly maintenance (which makes more sense now you are releasing a new web client). I was wondering if you could notify us (your users) beforehand, so the notes we were working at that time don't get lost. Maybe a web-browser notifications some minutes before would do the job nicely.
Unwanted tag search buffering
I see that tags are now implemented in this new web client: thanks for that! I just tried searching some notes using the Evernote search syntax, and it seems it is somehow affecting later queries. This is how I reproduce this issue: I look for "tag:A tag:B" using the search bar and all notes with tags A and B are returned. Then I try to gather the notes with tag "A" from the "Tags" tab, and I still get only these notes that have both "A" and "B" (notes with tag "A", but not "B", are not shown anymore). The good news is that later I can repair the problem by making the search "tag:A".
Accumulative tag search
In the desktop and mobile clients, we have a way to focus our search using tags in an accumulative manner. This is, a search for notes with tag "A" would reduce the scope of the next search by only suggesting the tags that go together with "A" in the last search result. I see this is still not implemented in the new web client. It would be great if you in fact add it! It would make the experience across platforms more uniform.
Thank you for your time and effort!