As a further note, we specifically chose the twist lock fasteners to resist wind pulling anything less secure off. We have been out West in 40 mph winds on numerous occasions and you don't want the wind snapping any tension style fasteners and your windscreen ends up down the road. Yes, we watched one go.
As far as the ladder issue goes, it's a five minute setup job, and since we typically park for days at a time, it was not a big deal. If you don't carry a ladder, though, it's a big deal.
And one last warning about pulling them tight - if they are not very secure, they will quickly abrade paint in a windstorm.
My experience, yours free! 8)