The window mollies from left side mid don't spread well and players can usually still find an angle from their right. The one thrown from stairs I've found to be pretty inconsistent and a little slow if I need to spend the time to make it perfect.
This is a super easy line up, one to two full steps and a jump throw, and relatively quick. The running jump throw from left side mid might still be a little faster however it is a trickier throw and I think it spreads terribly. This one covers both the left and right side of window forcing the player into mid if they try to take any angle on stairs.