When observing do you feel the need for lots of different focal length EPs'?
I don't really, and I think if you're only using the one scope that you could be quite happy with say 3 focal lengths (in a dob maybe the 21, 13 and the 8); the wide AFOV makes them quite flexible IMO.
You could also be very happy with one Ethos (or none) and a range of other pentaxes or whatever.
Another point, as well as being heavy, is that they dont have overly generous eye relief, so if you wear glasses it can be an issue for some. I dont understand how someone could be put off by the extra AFOV though