I'm not so much a lapsitting fan but my favorite thing is viewing intimate F/F cradle lifts. When a lapsit has a cradle lift position with the bottom girl's arm holding under the top girl's legs, that's almost as appealing to me as a cradle lift. It can convey the exact same intimacy.
As far as participating, I'm not a liftee so likewise I don't sit on laps. I do enjoy holding girls on my lap though, especially in that cradle position, which is also my favorite lift to perform.
So even though I come from the opposite perspective, I agree there's a similarity in the appeal.