Hi:
We work with a Bolex EBM at school.
The main disadvantage is a prism system that cuts -+30% of light to send it to the viewfinder. So you´re reducing your stock sensivity in 1/3.
The viewfinder is pretty dark and takes time to get used, and it´s located at the back of the body of the camera in a fixed position. For certain shots it´s very unconfortable.
Due to the prism system you should use "RX" lenses (reflex compensated) to avoid soft images at big apertures.
The shutter is fixed at 170º, so you have few possiblities of adjustment for flickerfree operation.
The camera is pretty tall with the motor under the body, so the lens center is very far from the tripod plate.
But anyway is a good camera. It´s been serving the school for a long time without noticeable problems.
Good luck
Alejandro
