Adblock works 100 percent all the time ,ziltch zero ads.
Any other advantages to premium? not interested in offline downloads but I would be interested in better audio for instance as I use a usb DAC.
I think it comes down to how you consume YouTube content. I watch it on a lot of devices which don't support adblockers (iOS, AppleTV, Sky Q Boxes and a LG TV) but paying the £1.11 a month is totally worth it. I also like the little premium feature which lets you continue a video on another device. Nothing revolutionary but I can't go back to regular YouTube.