My thoughts.
The game on the whole felt very "bleh" to me. It's not bad and it kept me entertained far longer than Rift did mostly owing to the interesting class quest line. The mechanics of the game feel like a step backwards from WoW despite how hard it is trying to copy it. The combat still feels unresponsive, the skills feel uninteresting and they don't synergize with each other in interesting ways that create a right way to play the class and a wrong way to play a class (at least with the Sage). You can just mash buttons and get perfectly acceptable damage output. In WoW, the skill design is much more directed. You know exactly what order you should perform your skills in, exactly when you are going to maximize your damage output in meaningful ways by executing correctly. Here, it didn't seem to matter as long I was pressing a button on every GCD.
The talent trees are just boring. I didn't look forward to getting even one skill in the entire Jedi sage tree. Most of them are still things like a 6% increase in damage on a skill or a 10% reduction in force cost. There are a few that attempt to introduce interesting mechanics to the class, but even those didn't really change anything. I only reached level 25, but even looking up the tree I didn't see any core abilities that the class would revolve around later on. In WoW, your character feels like it evolves as you progress in levels and gain new core talents that the class depends on to function. Here, you just sort of put points in things and maybe notice the damage on a tooltip go up by 10 points.
Along with these mechanical issues, the enemies I was fighting never fought interesting. Trash regular mobs rarely do anything special, but here they were never even differentiated from each other. I couldn't tell when enemies were doing things I could interrupt or performing skills that I should try to avoid. This was particularly salient during elite and boss fights. Bosses were just an endless parade of tank and spank encounters, never doing anything interesting or forcing me to think my way through. These were only the early levels obviously, but if I can keep beating on the WoW horse, the old world redesigned dungeons had fucking awesome boss mechanics even as low as level 15-20.
The planets structure feels odd as well. I felt like I spent most of my time in some enclosed corridor on Coruscant and Nar Shaddaa. Obviously both of these planets are designed that way and there are open world planets as well (Tython, Taris and Tatooine were, obviously) but it still watered the experience down for me. At least you get an illusion of free movement in open world planets. The corridor planets were just boring to look at and to play. That said, they are nicely differentiated from each other, with each planet having its own sort of identity and style of sidequests, which is MUCH more than I can say for most MMOs.
The strongest point of the game was the story quests for your class. They gave a nice sense of intrigue and impending sense of gravitas to the things you were doing. It wasn't quite on the level of the storytelling in KotOR 1/2, but that's because it's still constrained by being an MMO. This leads me to my greatest complaint about the game: it's trying to be two things at once that don't jive well together. It's trying to be this old-style Bioware cRPG centered around your character and this big overarching story while also being an MMO with hundreds of other, equally important player characters running around. You get this sense of cognitive dissonance about whether or not your character even matters with hundreds of other most important persons in the galaxy running around.
The choices in the quests are an illusion. You get light and dark side alignment points, but beyond the cosmetic they seem to be completely meaningless. Your choices don't ever actually affect the outcomes of the story. There are no places where making an evil choice branches your story off in a different direction like in a true RPG. You look at something like The Witcher 2 and you realize that the entire second act of the game hinges on the choice between Roche and Iorveth in the first act. It's a completely different game depending on what you do. This is common in a real RPG but it just doesn't fit into an MMO.
The Republic vs. Empire mechanics of the game seemed nonexistent as well. It didn't feel like my character was taking place in a cold war. Never once did I encounter a member of the opposite faction. None of the quests had anything to do with the other side except vague hintings that the main quest was the work of some fallen Jedi turned Sith lord. Sure, there are PvP battleground of some sort, but world PvP is so much more interesting, and it just never came to any kind of fruition.
There are nitpicky complaints I can indulge as well, such as the slow ass movement speed and the fact that about 80% of your time in the early levels is spent laboriously running back and forth between quest objectives through boring areas with nothing interesting happening on the way. They should give you faster movement speed earlier. I'm a fucking Jedi, I should be able to use the force to run really fast all the time. There were all sorts of little bugs and unpolished things in the beta as well, such as the animations and companion interactions with elevators which got me killed numerous times. I know it's a beta, but the game comes out in like 2 weeks for the preorder holders, this stuff isn't going to change significantly in 2 weeks.
Overall, it's just another mediocre MMO with one strong suit in its storytelling. However, even that is held back by nature of it being an MMO. I think they would have been much better off just making KotOR 3 and continuing unambiguously with the story of Revan and the Old Republic rather than this weird, psuedo-MMOcRPG thing they've managed to concoct.