hey pete
I went through your dilema 6 months back .. and went with the 10"
I have thought once or twice the 12" would show me more .
Having had a look at glencs nice 12" dob .. the portability issue you raise
is pretty evident .. the views are great .. but you cant help notice
this IS a big scope ..I couldn't imagine walking this baby down the hallway , down the back steps across the yard every night without the knees giving out ..not to mention bumping/nudging stuff along the way.
The truss option mentined is where I'll go if I decide to go bigger .
take care ns