Tricky Dicky formulated the question :
I am looking to install an extractor fan to remove vapour from a shower and
toilet niffs. Are inline fans better than ceiling mount fans and where is the
best place to locate the grill with the toilet pan and shower at opposite
ends of the bathroom. I would rather not site it above the shower as fitting
is a little awkward not to mention claustrophobic owing to the shallow angle
of the roof approx. 22deg.?

Always best, at the opposite side of the room to where air comes in.
Idea is to prevent steam and smells escaping via the door, drawing air
across the room. Usually that will be directly opposite the door.