The generic sensor widget allows any parameters to be created and then displayed. I have this to show how frequently my sump pump is running...
Program.AddVirtualModules("HomeAutomation.ArduinoBsmtUtil", "Sensor", "homegenie/generic/sensor", 4, 4);
////
var module4 = Modules.InDomain("HomeAutomation.ArduinoBsmtUtil").WithAddress("4").Get();
Program.RaiseEvent(module4, "Sensor.SCPH", data[AM_SUMP_SCPH], "Sump pump cycles per hour counter on arduino ");
There are benefits to using the pre-defined ones you mention though (if they exist for your parameter)... some force an icon to show up for example.
I also have a generic sensor widget for the "multi-sensor" my Arduinos implement. I added "uptime" parameter so I can see if they are resetting frequently (My ESP8266 started resetting too frequently after updating the arduino libraries a couple months ago).