There is no endgame. There's barely a sense of progression. I'm almost level 1000 and I'm still using a level 200-something shield, 400-something LMG, and a grenade from a quest you could do at level 1 because they have the right stats/bonuses. They redid the loot system recently to make drops past level 1000 (every drop is scaled to your level making grinding solo just as effective as grouping) more appealing but I'm only mid 900s so I can't comment on the changes. Items with nonsense stats like a sniper rifle with melee damage won't drop anymore though.
That being said, it's the best MMO Shooter with the best PvE I've come across. That speaks more to a lack of options than a testament of its quality. I don't think it would be too hard to fix the game but I think Trion is going to be too stubborn to give in and do it.
Every time I try to go where I really wanna be it's already where I am, 'cuz I'm already there XBL, PSN, Steam, Origin, BSN, GFAQs, MC: PhilOnDez
It's not good if you're all into MMOs and whatnot. Sure there's tons of people around, especially when you do one of the events around the world. But everything is solo-able.
However it's a pretty decent shooter/RPG hybrid in the same vein as Borderlands. It's not a lootfest like Borderlands, but the gameplay mechanics are pretty similar. Go into it thinking of it as a multiplayer/coop game and not a MMO and you'll probably enjoy it.
Oh, and the progression. It feels off, but in reality it's actual progression vs. fake progression like Borderlands. Some guy wrote a long as post about this and explained it, but I'll try to paraphrase it.
What's the difference between being level 1, killing level 1 enemies with a level 1 weapon, and doing all of that with a level 30 character/weapon/enemy? Answer: About 20 hours. In Defiance you and the enemies have as much HP as they're ever going to have. What makes your character improve is the skill grid you put points into and it does things like make you reload faster, find more ammo, move quicker, etc. And the weapons. A level 1 assault rifle does the same damage as a level 200 one, but the difference is the special abilities and attachment slots. Lower end weapons don't have abilities or many slots.