Great thread Af.
Even greater discussions/knowledge sharing between Mental and Les
I enjoy keeping my feet on the ground when observing. I'm 6' using an f4.7 14.5" truss dob. My feets firmly on the ground and on the odd occasion at zenith I may need to go on tippy toes....my point here is think about the portability/convenience aspect here. Ask if you want to be lugging another item out during observing time, whether it ends up being just a stool, step ladder or ladder.
I don't use a parracor (to reduce/remove coma aka seagulls), but having plonked one in, I do see the subtle differences of stars on the edge being pinpoint. To that end, one is on the way. I prefer using premium eyepieces when viewing as well.
At F5 I think you can most definitely get away without one.
Cheers,
Norm