I'm playing it on and off at this moment. You can get the full package off Steam for $10 [get 30 days free]
It is definitely worth the $10 and depending how involved you get the sub seems worthwhile.
Certainly a bit different than WoW though.
The bad things, from my january impressions:
1. poor animations (especially your own character)
2. ground combat is clunky and just plain bad imho (it is more realtime 3rd person combat) , sometimes you don't see animations fire and so you don't always know whether you attacked or not, that kind of thing.
3. collision detection is iffy . (walking through some objects, getting stuck on others)
4. The graphics are pretty old, but the open landscapes sort of makes up for it. Some planets looks better than others.
The good things,
1. It's Star Wars and certainly feels like Star Wars.
2. Space combat , yep, it's a totally different "career path", you can skip the entire ground combat leveling scheme and just become a pilot. Space combat is pretty much like Freelancer/Xwing and those types of games (fast actiony).
(With this i mean, you can actually have a different "space level" than your "ground level" )
3. Social side of things, if you roll on the more populated servers [i rolled on Starsider, the most populated server] there's alot of stuff happening. Unlike WoW with a linear zone design, SWG throws you in the equivalent of "Ogrimmar" or "Shattrath" right at the start. So you see veterans and lowbies coming and going. Each planet got a big hub with alot of activity there (and yes you can travel to every planet instantly right from the start, so if Tatooine (the desert planet) is getting old, go to another planet with forests and do missions there) .
I've actually seen more players "going about their business" in SWG as a lowbie than any other MMO in recent times , only WoW-Oggrimar-dueling-outside-the-city-gates comes close.
4. Sandboxy nature of the game, you can be a trader or entertainer (instead of a fighter), which means again, just like the pilot thing, is a totally non-combat career path. Yes, you -can- kill mobs, but you get zero XP for doing so, definitely a little mindshift, knowing that "kill 10 rats" quest you received will give 0 xp on a trader. As a trader you harvest and craft to level up, not quite my cup of tea doing -just- that, but it certainly adds a whole other angle to the game. Likewise with entertainers, they seem to be the buffers/morale boosters and dance and sing around in cantinas. I use them to get my death penalties removed and such.
5. And then there's the whole Player Housing and CITIES. You can even place vendors inside your house and sell your crafted items, but the cool part is how these player cities/houses are right there in the open landscape. You can enter houses, you can see it, if you log into a different server a certain spot might be empty and on another server it will be filled with houses..
6. They've added like a few weeks ago, the "Galactic Civil War" enhancement, which is kinda like Warhammer RvR. Except, it seems a bit more strategic to me. Basically take STormwind/Oggrimar in WoW, imagine that Alliance/Horde can "capture" these cities and take it over (literally flipping sides), well that's what GCW seem to do (Imperial vs. Rebels). Defenders can build defenses (using traders) during certain phases of a city battle etc.
(Also note, unlike WoW's Alliance vs. Horde, SWGs factions have alot more flexibility, you can remain entirely neutral too and/or pick a faction at any time . Yes if you DO pick a side, certain groups become hostile to you, which in turn might mean you'll be shot on sight in certain towns, but it's not like you're locked out of places or content. And everyone can talk to everyone,regardless of your faction choice... )
Overall, i'd say certainly worth a play, just to get an idea when people talk about "sandbox mmo" . I'm a little burned out on MMOs i guess , so i don't appreciate it enough , but SWG even in 2010 certainly made me go "hey, this is what an MMO should feel like, now if only they could fix the actual gameplay a little" .