I too have always thought the normal Central Heating controllers were far far too basic. After some investigation I decided on a commercial one, which does much as Dave's does, apart from remote control. However, as it also has proportional inside and outside temperature gauges (ie not just on/off at a single temperature) it also enables different temperatures at different times, and it builds up a profile of how long it takes to heat up. Using this it decides the optimum time to start heating to meet your specified temperatures depending on the outside and inside temperatures (as John suggested above), and it also enables far better temperature control than the on/off thermostat allows, avoiding overshoots and wide swings.
These optimisation facilities can actually save money, as heating costs are reduced, and also the house feels much more 'comfortable' somehow.
Presumably these facilities could be added to the A3000 version, with some considerable effort.