%X (Percent X)

It was a top-tier chart alongside I Want You when it was a 19, and it still is now as a 20. Both straight-on and mash are difficult...

One of the hardest s20s to hit straight

A chart that gets tougher as it goes. Be careful with gauge management so you don't make small mistakes before the late spike. Be careful not to mash the mid-section drills. For the late-section stairs and horizontals, you must hit them accurately to build hidden gauge, and for the final spike's diagonal twists, you have a choice between bracket-mashing or full accuracy. I'm terrible at bracket-mashing, so I cleared it with full accuracy. A tip: using your heels well during the diagonal twists makes it slightly easier to clear with full accuracy. Perceived difficulty is S20 mid-high.

What on earth were they thinking when they gave the previous version a 19?

How many people can actually hit that high-angle twist accurately to clear it? Let's just use 3-note brackets to get past the high-angle parts. Besides that, the stamina requirement makes it a solid mid-high.