Stepmania timing window question

[TheSeventhSign]

In Stepmania, there's an option to change the timing window for Perfects. It's from 1-7 and then Justice, or something along those lines.

What would you say FFR's timing window is in Stepmania terms? The default is 4, and I've only played Stepmania once or twice (I don't know what I think about it yet), but since I'm so used to FFR, I'd like some things to be familiar to me. I just found out the "Note" skin and that makes it a whole lot more playable.