Although it definitely does have many useful features, there are far too many bugs for me to justify keeping on using it.
Just to list a few that I've experienced thus far:
• Miniplayer still plays audio even after closing it.
• Switching to any age-restricted video results in a bug that won't allow you to play the video unless you copy/paste the URL into a new tab.
• Videos end for no reason while there's still plenty of time left.
• Autoplay doesn't work half the time, the button doesn't seem to affect whether it autoplays or not.
• Sometimes doesn't switch from the miniplayer even if you're scrolled up at the top of the page.
This being said, I would still recommend trying it out for a bit and seeing if it's glitchy for you.