It's a fair question.
Many people are not satisfied with their current controls. Manual controls can require frequent adjustment. With practice and experience one gets better at using them, but generally you end up accepting a certain level of over or under heating. Timer boxes and rheostats can simplify things, but you still end up having to chase the outdoor temperature changes with adjustments and things can be quite a bit off if you leave the house for the day or when you wake up in the morning.
Some people have thermostat controls that they bought with their stove. Typcially it is a bell thermostat or a more crude thermostat box, either of which works in conjunction with a timer that provides idle feed setting, and maybe it also provide a full feed setting (or this is set with the manual controls). These setups often result in widely fluctuating temperature control, though. If it is set to 70, for instance, the actual temperature in the room can swing up to 5 or more degrees above and below that setting.
This happens and the effect is strengthened by a number of factors, but the root cause is that coal fuel takes a long time (compared to electric, gas, oil, or hot water heating systems) to generate the heat being called for by the thermostat. This delay results in under and over shoots in the temperature of the space when controlled by a traditional thermostat.
Manual and timer/dial controls often result in even worse fluctuations unless they are at the hands of a seasoned coal stove owner.
And these fluctuations don't only result in discomfort, they result in wasted fuel as the stove over heats the space or has to overcome the low of a temperature dip.
The Coal-Trol Digital control systems work on a different principle than traditional thermostats, which allow them to feed only enough coal as is needed to maintain the desired temperature. It will maintain that temperature setting to within 1 degree of the setpoint, and while providing that level of comfort and ease of use you will be saving coal (at least 11%, usually more) by having eliminated those large temperature fluctuations. Of course, when a programmed or manual temperature setpoint change occurs it takes some time for the temperature to adjust, just as with any thermostat, but once at the desired temperature we maintain it within that 1 degree range.
We also offer additional features depending on the model one wants to buy, all of which are detailed at our website at http://www.coaltroldigital.com
Lastly, we're actively working on an automatic ignition module that will work with our systems. In addition to making it very easy (and clean) to start the stove, it will extend the practical usefulness of the stove further into the transition seasons of spring and fall.
So that's my shpiel.
As you say, if you're happy with what you have then there may not be enough reason for you to try a Coal-Trol Digital system out. But if you're seeing the kind of temperature fluctuations I described or after looking at our website and searching the forum's prior discussions on the Coal-Trol you see value, we encourage you and others to ask questions and hopefully order a system.
We offer a 3 year warrantee and a 30 day money back guarantee and multiple avenues (email, these forums, phone call, etc.) for customer support. System prices are from $250 to $450.
Thanks for your question. Ask as many as you like, that's what we're here for.