There must be some convention regarding the way ships orient themselves relative to each other, since there's no obvious reason in space that ships have to be oriented in any particular direction. Ships are shown "rightside-up" on screen, but there's really no physical difference if the ship is "upside-down;" the ship has artificial gravity and nothing would really change.
I've always thought the Excelsior/refit Connie had a certain stateliness that the more streamlined ships of the 24th century lacked. Later designs started to look more advanced, and generally cooler, but the movie era ships were classy.
"If you can't take a little bloody nose, maybe you ought to go back home and crawl under your bed. It's not safe out here. It's wonderous, with treasures to satiate desires both subtle and gross... but it's not for the timid." Q, Q Who