All the time. Been riding a while with fitter friends. I started months ago in trail, now I dial it back to eco on all but the steepest climbs and turn the assist off on flats. I carry the pack with first aid, tools, extra food, and water. I still cannot keep up on acoustic, but hopefully soon.
With emtb riding friends we generally cruise in trail, cover more ground, but not crazy fast.
With slower friends I leave it off or take acoustic.
I generally don't get my heart rate as high on emtb, as my legs feel it more than lungs (especially on low assist settings) compared to acoustic. But my legs seem to get a better workout, I guess it's the weight.