When we had our 5er I looked at those several times and wondered how they would work out in the long haul. When we got our TC (used), it had a one of those (just not the same make/model.) I suspect it had not been used from some time (due to the soap had half dried up in the tanks). I removed the tanks, flushed them out with water, flushed the valves out with water and it works.
DW and I think they are great! No messes, no chasing shampoo bottles, no chasing bars of soap.
Got a smaller single dispenser for the kitchen sink after the bottle of dish soap fell on its side, then emptied itself in the cabinet under the sink due to the change in temperature.