I have an Intenscreen in my Rolleiflex 2,8 F and I had a factory installed ground glass screen in the 3,5 Automat MXV. The Intenscreen is much brighter especially in the corner, it has a very fine "grain", but the exact focus is easier to detect on the ground glass (but only in the middle). I changed the ground glass against a cutted to fit Mamiya RB 67 screen, this works perfect for me. This solution was much much cheaper than an Intenscreen would have been. I'd not spent so much money.