Jerry,
If you are talking about the SMX controls versus the three black knobs there is no comparison.
We had the black knob controls on our 87. After a while we learned to set the temp at maximum cold, and when it got comfortable we would turn the knob back until it clicked, and turn it back very slightly to put it in the middle of the on-off differential range. From then on we never touched that control.
We left the fan speed knob in the middle, but sometimes changed it to get more air flow or less noise. The fan runs constantly, even when the condenser has cycled off.
Generally speaking the old controls worked, but required some effort on our part and did not have any real features.
The SMX is light years ahead of the old controls. Once the temperature is calibrated, you set your desired temperature in the window and set whether you want cold, heat, or both and away you go. The fan speed is automatic if you like that or you can set any speed you want. You can use it to dehumidify, and basically do just about anything you ask of it. When we have shore or generator power we just power the cruise airs and let the SMX controls take over. At night when it gets cool the fans are virtually shut off, during the day when the heat starts building the condensing unit and fans work as necessary to maintain your set temperature. If it gets cold enough for heat and that is what you selected, it switches from cooling to heating without any effort on your part.
When SMX came out (early 90s I think) converters were installing those controls in place of the old controls so the units can be upgraded.
Besides the closet carousel I can say for sure the SMX controls are the next biggest advantage my wife sees in our new coach compared to our old.
Jon
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