Upload & Sell: Off
My wife and I don't present ourselves as the techy type of photographers, so we don't use these. Presenting that relaxed image is important for us as we believe it is important to our clients.
Additionally, my wife and/or our associate shooter always communicate in the downtime between big events (right before the ceremony, right before the grand entrance, etc.), and from there, we signal each other with hand motions and such as necessary, but otherwise we kinda' know where we'll be and what we need to do.
I totally agree with you. I mean, my clients know I'm pretty high-tech and a nerd, but I definitely don't want to come across as secret service when I'm shooting a wedding. Like you, my assistant and I go in with a game plan and generally don't need to communicate all that much when things are happening.
With that being said, there are times when a discreet wireless communications device that doesn't stick out like a sore thumb would be beneficial, so I'm really only looking for something that isn't overly visible.