I really don't see any difference in terms of sitting versus standing between a 10 inch F/5 versus a 12 inch F/5. Both are too short to allow standing and both are best when the observer sits on an adjustable chair such as the Starbound.
Jon
True, but upright the 60 inch is less painful, by 10 inches, for standing observing. Ideally for height a 12 F6 would be ideal.