Dear "Technical support" - So what you are saying is that the "high speed sync" feature of the Godox flashes is a feature of their long flash duration?
If I want to freeeze movement in daylight I would be better served by the Godox at 1/8000 or 1/4000 of a second?
Or should I stay with Einstein? I can't keep thinking that if I want to freeze movement in daylight outdoors (while underexposing the sky in the background), I'd be better served by short shutter speed?
Please tell me I'm wrong as the Einstein/Vagabond package is mightily tempting
It really depends on what Godox flash you are talking about. BUT, all high speed sync involves a long enough flash duration to open and close the shutter.
Freezing movement in high ambient light is tricky. The flash at x-sync may freeze the flash lit parts, but parts lit by the ambient could still blur. If you use High Speed Sync, or any related technique, you get reduced effective power from the flash.
If freezing movement in bright light is an important part of your photography, then you may want to invest in a camera capable of syncing at higher speeds. This could mean using a 7-8 year old D70 or using a newer Fuji.