Glory, your comments are interesting to me because I’m 6 feet tall worked in a shop my whole life and I would say that the convenience factor starts diminishing above 8 inches as far as commercial particle board ones go. And I would advise someone that portability and the likelihood of you dragging it outside outweigh aperture considerations. I’m not saying that you are right and I am not saying that I am right, it is just interesting that we see things differently. I think the advice of -you’re just going to have to try it out- it’s probably the best and each person can come to their own conclusion. I have only ever looked through my own scopes and I have had a GSO 8 inch Dob, a 12 inch collapsible skywatcher and C8 on a GEM, and I would be hard-pressed to say that the 12 so substantially outperforms the 8 to the point where it would be a dealbreaker.
P.S. It’s also possible I somehow have a dud 12 inch mirror and my 8 and C8 are better, and/or my collimation methods are substandard and maybe that accounts for the performance difference. Just a noob alert disclaimer.
Your comments underscore the principle that just as big trucks weigh more than little trucks, big cars weigh more than little cars, a feather weighs more than the money in my wallet, etc., Big dobs weigh more than little dobs. In other words, no one should be surprised that if they want more aperture, they necessarily get more weight and size. Different people have varied costs they're willing to pay in exchange for having a larger mirror (harder to move, more storage space required, more steps to assemble etc.). Pertaining to the topic at hand, permit me to re-state what I've said above in a different way: being able to see the spiral arms in M101, the way Horsehead popped into the eyepiece this weekend, the spiral structure of M33 are well worth lifting an insignificant 200 lbs. I would run a mile to see that again, and for me that is saying a lot. I'd also like to state that there is one other aspect about the Orion and even Skywatcher that I prefer over the ES or even an Obsession style classic: The altitude bearings and hence center of pivot is significantly higher off the ground than the center of pivot of the Obsession style arrangement. As a result, for lower altitude observations, the eyepiece is higher off the ground for the Orion & Skywatcher than for their rivals (which means less hunching). Of coarse I don't mean to say by any stretch of the imagination that my xx16G is better than an Obsession except on this point IMO.