1st: Stop Freaking Out
Let’s get this out of the way: YouTube, doesn’t change the design arbitrarily just to annoy you. They change it to try and improve it – and they aren’t just guessing at what might be better. YouTube does A/B tests to see how changes affect things like the number of videos watched, channel subscriptions and advertising revenue.
It’s reasonable to assume that YouTube releases new designs when user time spent on the site increases, even if you personally don't like change. That’s good news for video creators and viewers.
That being said, it’s still possible to have strong feelings about changes to the site which, as someone who spends far too much time on YouTube, I certainly do.
Aesthetics
While I do have complaints, in general I’m pleased with the redesign. It's lighter and more spacious than the previous cosmic-panda-based design that I was not a fan of. It was cramped and dark and and heavy. The new design is more in the Google+ aesthetic – which some people don’t like – but l do. The bold colors, particularly the red for the page selector, on white are very Google-ish to my eye.
But, colors aside, the first thing you’re probably going to notice is the odd choice of left-aligning the whole site. It’s not really noticeable on my laptop but looks incredibly dumb on a large screen.
It's difficult to A/B test for 'looks dumb'.
Thankfully, the channel pages remain centered, but it gives the impression that some poor YouTube engineer forgot to close a DIV tag on the rest of the site. Also, the left alignment really triggers my OCD when watching videos in the big (but not full-screen) view:
Video: Y U NO ONE INCH BIGGER?!?
Comments: Better, But Still Terrible
The addition of user icons to discussion is much welcome. The icons make regular commenters and friends in discussion much more visible.
The quality of comments, however, still leaves something to be desired.
But, YouTube can’t ever improve something in comments without making something worse. At the bottom of the page there used to be a link to see all comments which has been replaced by a ‘show more’ button.
It might not seem like much of a deal, but the ‘all comments’ link allowed you to sort comments by thread, which the ‘show more’ button does not. YouTube threading is terrible, but better than nothing. I thought that the feature had been removed entirely until I found it by accident lurking in the 'all comments' header that looks exactly like the other two unclickable headers.
You’ll Watch What We Want & You’ll Like It
YouTube now dumps you on the ‘what to watch page’ by default. Perhaps it’s good for casual users without many subscriptions, but with 60+ subscriptions it’s a jumbled pile of crap with out-out-order uploads mixed in with playlist updates and videos people liked.
YouTube seems to treat subscribing to channels as merely information to feed into their algorithm to better suggest what you ‘really’ want to watch. I subscribe to channels because I want to watch them – and YouTube’s design changes have caused me to often miss new videos uploaded by the people I follow. More and more I find myself leaning on the subscription digest to guide my YouTube viewing.
Weirdly, 'What to Watch' recommends videos I’ve already seen. Also I’m not sure what the ’Hide this Activity Button is supposed to do. My guess is that it’s supposed to be like the long-lost x button, but the wording is unclear at best (does it hide just this video or all videos from that channel?) and, when I tried to test it out of my own upload page, it seemed to do nothing at all.
Just what is this button supposed to do?
All I want is a reverse chronological order list of uploads from the channels I subscribe to where I can remove the videos I’ve already seen. Is that too much to ask?
YouTube Should be the World's Best TV, Not the World's Worst Social Network
The social integration is hideous and has to stop. If I want to see what videos my friends are talking about on Facebook, I'll go to Facebook. Actually, I never go to Facebook in the first place, because I'm not really interested in what people I knew 15 years ago think is funny.
YouTube need to make the sit-back-and-just-watch-something experience better, which brings us to the next section:
Playlists: Vastly Better
The old, terrible, buggy playlist scroll along the bottom has been replaced with a more elegant one alongside the video. Playlist deserve this much nicer implementation. YouTube is too 'active' an experience right now, with users having to choose a new video to watch every couple minutes. While that might not seem like a big deal, decisions are tiring. The nicer YouTube can make playlists the longer people will watch.
TL;DR
In summary, the new YouTube design is better than the last. It's visually an improvement even though it still has usability issues and is developing social-network-wannabe issues.