Yeah, I have a few at home. I stall haven't set them up. The biggest downside is that currently you have to have a device on in the house running the BT service to make them work. That means you can't leave the house with your phone if it's the primary controller or none of the buttons will work... I think they're working on a Mac/Pi/Win service, but haven't checked progress on that for a while. 

How quick is the response from button press to action? These would be perfect to control our lights but not if there is a big delay..

It was only a second or so when I was testing the button to make my phone ring. Not great, but workable. 

Disrespective:

 

It was only a second or so when I was testing the button to make my phone ring. Not great, but workable. 

 

Hmm. I suspect that isn't going to fly in comparison to an immediate response to a light switch.

Back to trying to find a solution!