How sensitive is tagging on the PC version?

Unfortunately, the keyboard controls for Jet Set Radio are pretty terrible. Upon launching the game, you're met with the following pop-up:

This, unfortunately, isn't very intuitive when it comes to tagging sites in the actual game.

After some trial and error, I discovered the solution for tagging areas such as the one in your screen shot.

Right before this screenshot was taken, I had a single down arrow. I managed to complete it by pressing S. However, upon completing that, I was met with what you see here. My first two attempts at this ended in complete failure. Eventually, I learned that the appropriate pattern for this particular arrow was: S > D > W. If I didn't do it fast enough, it failed, wasting a can of paint. If I did it too fast, it failed, wasting yet another can of paint.

So, long story short (too late!), the keybindings for keyboard use during tagging is horrible. While it doesn't require a gamepad to play, you would probably find your experience much more enjoyable if you used one.