For those who have used RE ball valves know they are worth every penny. Most hardware stores carry cheap ball valves that over time get hard to turn and can break pretty easily. RE ball valves will last a lifetime with super smoother operation.
We are always recommending the use of unions on plumbing as well. Unions make everything from plumbing and maintenance easier. By having a union on each side of the ball valve allows for easy removal of hardware, or isolation of equipment for service.