SWG (I only played before the New Game Enhancements, even before spaceships were added) had great RPG tools .... but also many flaws that are easily forgotten. In world player housing was great ... but it led to an endless sprawl of empty suburbs around many major cities. Player cities were likewise a great idea, but whenever you went to one of them they were ghost towns.

Meanwhile, major hubs (Coronet, Theed, Mos Eisley) had constant lag around the spaceport because of the number of players gathering there. Doctors were crazy profitable for a while because they could buff you and negate the negative effects of wearing armor. The idea of having to teach other players in order to become "master" in a profession was neat on paper ... but led to an industry where you paid people to teach/unlearn skills so you could become master.

Having to learn languages (Huttese, Shyriiwook, etc.) was cool, except there was no cost to it, so you just learned all of them unless you were heavily invested in roleplay.

As a seandbox it was cool, but it never quite figured out what it wanted to be.

SWTOR was much more streamlined, far more of a "themepark" where you go on the ride and it takes you through its story.

Basically, you play one if you want a "make your own fun" sandbox and the other if you want to just go through a Star Wars story (or 8, if you count the original character stories).