Thank you for making this post @liberosist. I absolutely do not like the new UI. I had no big issue with old UI, I loved it.

First of all, why not give users an option to go to old UI with a "classic" link? So many major sites have done that when they made major changes to UI. Why break something that has worked fine?

It seems to me new UI is targeting easy changes for multiple size device supports. But I should say I have used old UI only multiple phones, tablets, pc and mac. It worked just fine on all of them.

Top line with username, etc should be at the bottom. I think a title should always be at the top. Title tells the most about the post. username, rep, category, time, resteemed, etc they all should be at the bottom before the upvote, resteem, etc line.

I don't think there is a need for sidebars to be visible by default. They should be collapsed, and only accessable upon need. That can give more real estate for more info on the post and/or more condensed view.

Toggle view is good, but if it doesn't give a more condensed view or two-pane layout, I don't see much use for it. As many have mentioned already, we would like to be able to see as many posts as possible.

Filtering option would absolutely be great.