Today I installed a water heater in the guest house, the second to last utility room appliance to be installed before the water heater. Since the only major plumbing in the guest house is going to be a bathroom, a fairly small water softener with a built in brine tank (versus a separate tank) was a great option.
It was extremely easy to hook into the rest of the plumbing, using two flexible sharkbite lines that connected the water softener to 3/4″ pipes.
I’d highly recommend the all-in-one water softeners to anyone as long as the water throughout is enough to meet the needs of a given plumbing project.