UA will have 777s and 787s on some flights like ORD-SFO or SFO-IAH/DEN where they are cycling through to their international flights.

Small commercial flights are fun. Did DEN-TEX-DEN a few times on Great Lakes' Beechcraft and Chiang Mai to Pai and back on Kaan Air Cessna Caravan.
I get people may not liking turbo prop planes but I don't get how a nervous flier would be more comfortable in a 767 over an A320.