About 90% of positions of the scrollbar are unusable. You have to scroll like crazy to find that specific position that actually displays the page correctly. Horrible.

The page introduces another parallel scrollbar (that has the same function as the built-in scroll bar) and it works really slowly and breaks the built-in UI. At web designers: you have a built-in UI, everyone it used to it, it works, it is tested, use it!

Scrolled like a dream on this Macbook. I didn't know it had issues while posting.