requesting real life experience with 904 lock-up with manual switch

I'm building a Dart for long distance travel and am considering using an electric trigger lock-up 904 with the wider spaced gears ( 2.74, 1.54, 1.00) and a lock up converter. To make things simple I was just going to install a manual switch to activate the lock up on the open road. Is anybody out there doing this? What are your experiences and what pitfalls have you encountered?

thanks for the help!!!