I've used and own 4 different 150 mms: old and new El-Nikkor, old and new Rodagon. None of them Apo. There was not much difference between the two old ones, the new Rodagon was slightly better (sharper and more contrast) but the new El Nikkor (new=without the knurled ring design) beats the rest very visibly, being more contrasty, less fall-off, and sharper at the f8. Tested only with diffusion using a Ilford 500H light. YMMV...