My evaluations have determined it's the most valuable application any utility can have in production; and there was no bias in my research either!
Maybe Rick Frymyer can assist with any past ROI as well as other customer responses.
I can't put a dollar value on it, but we've been using Responder since 2006 and it has made outage management much more efficient and reporting much easier. Our prior system was post it notes on an board. We have about 50,000 meters. It did take a couple years for full buy in by all the operators, but I think they all generally like it now compared to the paper way of managing outages.
Within the last year, the system operators have starting using Responder for checking their switch orders. I know of one occasion by using that tool we avoided knocking out power to over a 1000 customers.
Feel free to contact me for more information.