I had a Mandala Hashberry pheno a few years back that was super Smooth. Not the most powerful bud but tasty and so good to smoke. The older heads in my area still ask and talk about it...
Ime my dankness strains feel heavy in your lungs. I have a feeling potency has a little effect on this as lighter strains tend to smoke easier in my opinion.
Fruity smelling ganja always seems to be smooth smoke. Like blueberry or blue dream. I tend to think the smoothest smoke is not the most potent though.
Purple ganja tends to be smooth yet sometimes lacking in power.