I'm not sure where the complications are coming from, its all very subjective. Generally though heating controls are conflictive because they rarely get used...even simple on-off ones cause grief. The best controller is probably the one you dont need to touch, which is what these controls amount too.
My organisation "Ecotechncians" has a significant number of these systems installed as retrofits with people of all ages in the London area. Indeed the people who are usually classified as problematic (over 60s) take to them really well, simply because they need very limited intervention. In terms of simplicity of installation these system occupy less space and take less time, but they do have to be commissioned correctly (average time 5 minutes!)
One of our recent projects has been to replace condensing boilers in flats with UFH. The solution has been installing a dual temperature combi boiler to replace the existing combi, a programable internal sensor and an external sensor. The heat curve and range rating facility is in most condensing modern boilers and the boilers have there output lowered to match the likely heating loss of the flats. The boiler pumps are man enough to run the entire system, so a pump is removed saving energy . All zone controls are removed, saving even more energy, and ensuring that there is a continuous open path between the boiler and the floor. Heat output of the boiler is calculated using the outdoor temperature (averaged over time in some cases) and moved to the floor zones with no valves. Heat ouput of each room can be varied by reducing the flow of water, by closing a valve. The average flow temperature is around 27c (this is wooden flooring rather than screed) and levels of comfort are very high.
The 5 year old condensing boiler removed were quite simply mis specified with an excess number of controls with no consideration for condensing technology or ultra low temperatures heating system design. Standing losses were huge and wasteful because of the use of mixing valves and actuators on the UFH manifold.
The most efficient way of heating a space must be to match the heat output of the heat generator to the heat loss of the building varying the flow temperature, which is a way of varying the kilowatt output of the boiler.
For UFH to be self regulating the flow temperature does have to vary, as the building heat loss will vary with outside temperature. Again the greater the insulation the less importance the outdoor sensor, but what has to be avoided is ramping up flow temperatures unnecessarily forcing the heat generator to be in efficient.
If one is going to chase the Negawatts, then one cant exclude the control system...merely because it requires someone somewhere to understand it!