I did not read all the posts.
I think the difference between ceramic and radiant heaters is this:
Radiant heaters are just that. The oil in the heater is warmed up and that oil circulates inside the radiator. But the heat coming from that heater is slow to spread through the room. But, once the room is heated, they are good at maintaining heat longer once they are turned off. Their cool down is slow. They also make absolutely no noise.
Ceramic heaters produce heat instantly and air is forced through the heating coils with a fan, blowing that heat away form the source faster. Plus the fan helps circulate that heat. Actually, this makes for a steady temperature rise in the room as the fan constantly circulates, pulling in colder air, discharging warmer air, fill the room. It's not necessarily faster than the radiator type, it's just more even through the room. Unlike the radiator type that is very warm near the radiator and can still be 20 degrees different 10 feet away.
The down side of the ceramic heaters is the fact, when they turn off, the heat is off immediately. When the heat turns off on the radiator type, the radiator stays warm, until it's cycle turns the heater back on. The temperature change is not as great as a ceramic heater.
Each one has their plus and their minus. It really is a matter of what works best for you. We started with oil filled and we are now using ceramic. For us, the "instant" heat is more satisfying.
In a way, think of two types like the two types in a home. The oil filled is very similar to all electric heat in a home. The ceramic is very similar to a forced air heat in a home (if the heat source is gas, propane, or electric), it's the fan that circulates the heat.
That is the difference.