On the plus side, reading and interacting with YouTube comments is a dream now -- big kudos to them for that! Also, there are lots more context menus now where you can swipe up or down on an element to interact with it. Overall the update is more good than bad.
The bad: the like and dislike buttons seem to have disappeared. Also, in the subscriptions tab, that area near the top where it lists your more preferred channels no longer announces channel names. The workaround is to find the "more channels" option to the right and double tap it to get a list of all your channels, but it's still a bug to be aware of