It's not pure Heise, obviously. I usually follow Petrus F2L-1 (which takes me around 25 moves in a speedsolve because I
only start on the Yellow-Blue-Orange 2x2x2

).
Then it could take anywhere from 3 to 20 moves

to reduce to a 3- or 2-corner case.
So, probably 25+12+10= greater than 47 htm on average. But these moves tend to be highly [RU] concentrated after the 3x2x2. I'm going for speed, not efficiency, per se. But I guess there is some balance that needs to be found.
Porkynator probably gets <45 htm on average LOL. He knows so many FMC tricks, that it's not even fair. Also he can identify the correct commutator/conjugate in microseconds! I still use R' D R D' LOL!
I could definitely be faster if I always used ZZF2L, but I don't think that's the spirit of Heise.