The Gefell hypers always amaze me. I've never pulled a bad tape with them.
Back to wind screens for a moment, we had a 1 day festival Saturday, really windy, like merch tables blowing away, etc. I sas running Gefell cards and big ass Shures, and that was the first time I've had rumble with the Shures. I switched on the 50hz HPF on the V3 and that was enough. Interestingly my daughter had the AT4050ST (mis/side LD) with a U89 windscreen which wasn't bothered as much. I wonder if it had to do with direction, wind was coming from behind the mics, right into the musicians faces.