1)I don't think one is 'better' than the other, but as one who likes to put his hands inside their PC often, the SB 802 allows for some extra, and beyond the norm setups.
Both are good, though I see the SB 802 as mechanically superior, in part due to the extra configurations.
Consider flipping a coin...
2)Airflow is dependent on factors like your hardware selections, fan positioning and personal fan curves. No solid yes/no answer for this one.
3)AIO/CLC compatibility, Lancool III appears to be slightly better, but it has a catch 22 with top mounted 140mm class coolers:
"Note: When installing 280mm or 420mm AIO, please do not install ram height taller than 44mm."
4)Silence: Gonna be virtually the same, since I'd imagine you'll be applying your own fan curves to keep things within your comfort zone regardless of which case you chose...
5)More robust? Both are big, heavy cases as far as my back would be concerned... would not be looking forward to maintenance time.
SB 802 has one less side window, which is one less potential exploding glass incident, because freak accidents can still happen to the most careful of us.
Also, you may not be interested in putting your cable management skills on display, which the Lancool III kinda forces on you, unless that side is hidden against a wall or something.