Oh I know
I hate it when a design change just rips off some important features. On Facebook, I hate it when the friends name above the chat tab is no longer clickable and I hate the way that you see a random list of friends (showing both online and offline friends) on the chat panel at the bottom right when you can only see online friends there on the ealier Facebook layout.
The only bad thing I disliked on the new Youtube layout is that the link titles of the related videoes at the right side are now shown with black text when it used to be blue or violet if that link has been opened before. Now I can't see which is blue or violet unless hover my mouse over them. It got somehow inconvinient.
The biggest annoyance on YouTube now is on the default main page of channels they don't show the date the video was released, and they're a jumbled out-of-order mess in my opinion which makes it difficult to follow a channel and skip videos I've already seen.
Now I much prefer to click the Videos link at the upper left on channels
as it shows all available videos logically in proper order.