Well.... from what I can see they have some utility in rental stock because some students and people who rent regs do not take care of them very well. It just lowers maintenance costs/effort if these regs are in rental stock, which for a large dive centre can be a big deal.
R..
The only catch with that is that the ACD is not shown as available in the Aqua Lung Calypso, which is the most likely regulator found in a rental fleet. Granted, as a flow-by piston first stage design is probably as reliable as you can get.
The ACD comes standard in all the high end Aqua Lung regulator, which are not the regulators normally found in a rental fleet.
The ACD can be an option for the Aqua Lung Titan, which could be a candidate for rental gear in a dive center that would like to cater to the higher end market. Actually that is such a good regulator, it should be a candidate for most any application, including rental fleet. (This is just my opinion)