drh's case is an exception too the rule. He is the only case I have heard of where a bird shied from a blind. I use them ALL the time, open or otherwise. I never brush my Double Bull during turkey season and actually hunt with it smack out in the middle of pastures. Turkeys are just oblivious too their use. It makes it much more comfortable to sit on regular stools/seats off the ground (and out of the chiggers and ticks) and camo isn't even necessary (I recommend covering the windows with shoot through mesh). Hunting with kids or restless adults is a REAL bonus for the blinds as well.

I consider my blind as much an integral part of my turkey equipment as I do my calls or shotgun!
RA