I have 2 lenses for my hassy 501cm, 60mm and 150mm, i have one issue with both, the issue is that i bought LEE adapter ring B60 to use on both [or say on 60 for wide outdoors] and the adapter never stay on it, i feel it is not the right fit or the adapter is not designed fine or whatever reason, i have another adapter but it is step [up or down] ring and it fit perfectly, so i really don't know how to solve this issues.
Second thing, i borrowed a lens 80mm C from my friend [and i gave him my 150CF], me and him are hating that 8mm C lens, either it is bad series of lenses or that lens has an issue, but he can't try to send it back for replacement, i don't know how to explain the issue with the lens, but anyway it seems i will stay with CF/CFE version anytime i can.