I would concur with the 8" as well. Don't get me wrong, I don't even have a telescope !
However one thing that always impressed me was the time I went to my local Astronomy club for an open night. Of all the scopes that were out there the President of the Society had an 8 inch Dob and it was great, simple in design, portable for its size but with good aperture. We looked at the moon and it was more impressive than some of the lot larger, more expensive scopes around.
It was also the scope that we talked the most about for the night. It certainly took me by surprise given the company it was with.
