Interestingly enough, we had one of our Tae Kwon Do roommates stay late for an aikido class last night. He had some ukemi training, so Sensei had us defend against kicks. He had us in hanmi handachi, so nobody had to kick really high or fall from a great height. We brushed aside the front snap kick and wrapped our hands around uke's calf and shin (no grab, just wrapped around). After the fall, we applied pressure to the tsubo in the inner thigh. Fun stuff.
I think it would be unpleasant from a greater height. I saw one of my sempai scoop a karateka's ankle and just ENTER. He irimied right into the guy and sent him back quite a ways. He didn't try to kick him anymore.