Some impressions so far...
I've made it to level 40. So far the questing is okay, kind of MMO typical but faster progress, so you don't spend so much time in any given area. Surely subjective of course.
I feel like they provide a decent amount of activities - I never complete all the dailies. Crafting keeps you a bit occupied, managing companions is a nice extra, there are lots of collectibles (companions, artefacts, epic gear, lore entries, achivements). Game doesn't feel grindy at all, which is nice.
Obviously can't comment on "endgame" yet.
I do like the combat system. I've only tried PVP once but it seemed okay, especially since I spent a lot less time crowdcontrolled than, say, in WoW (where pvp usually equals stunlocks).
One thing that surprised me was that they actually have a really good website ("gateway"), sort of like the WoW Armory, to manage your characters, inventory, mail, auctions, and it comes with a fairly neat browser minigame, too...
my biggest problem with the game is that they seem to push the microtransactions a lot harder than GW2 for example. It's not pay-to-win but payment items such as crafting stuff, companions etc are much more important than in GW2, which is mostly "cosmetics".