1. Wonderful friends and contacts. I have 714 contacts at the moment (so not too overly amount) and something like 50 friends. They are the biggest asset of Flickr.
2. Fast to add faves and comments from the new homepage without opening the photo. Shots are big enough to see them clearly.
3. Recent Activity page is as before. I am using this page a lot to see what is happening.
4. Easy to embed photos to my WordPress blog. Flickr also works nicely with iPad Blogsy blogging app which I am using.
Now that I have tested few photo sites (e.g. 1x, 500px, Ipernity) in addition to Flickr it seems that I do not have time to use many (not even two) sites simultaneously. I have also my blog to care for.