Completely agree!
We went to Brighton from the midlands last Thursday, M1, M25, M23, A23. The bottom end of the M1 and the M25 were busy, but moving. The variable limits were all over the place, 60, 40, 50, etc, etc. It seemed like every gantry had a different number on it.
This completely disrupted the trafic flow. Instead of being able to proceed at a steady, but reduced speed, there was constant braking, speeding up, braking etc. Yes, you could just stick to the minimum speed, but then you would be constantly being overtaken by everything else on the road, including artics, which is not a comfortable feeling.