Not that the game doesn't have glaring PvE faults, but leveling is fairly-set your own pace when it comes to the heart events. If I have anything to complain about on that front, it's that combat gets a bit stale. There's like 2-3 skills per weapon swap that you just go through, so sometimes there's periods where you just sit there waiting for your cooldowns to end. When you have only 5 abilities to work with (not counting the 6-10 skills, which are either passive, situationally useful, or on restrictive CDs), some of which aren't necessary or effective in PvE, any cooldown beyond 10 seconds is incredibly mind-numbing. This is only sort of exacerbated by the leveling curve, which ensures that you pretty much are limited to this type of PvE for hours.
Even the initiative-based thief doesn't really circumvent this problem, and the engineer doesn't have access to all his kits until a later level (and reading up, you wouldn't use most of them because optimal play requires the use of other skills). I don't feel necromancers and warriors aren't worth mentioning in this regard. From a concept standpoint, elementalists might be right up my alley, since attunement switching and combo-fielding might guarantee at least some degree of frantic button-pushing action.
So I find myself just chilling and exploring areas on my Guardian for now. I might be unusual that I prefer the jump puzzles to the combat.
I like the premise of it, the new take on levelling but I also feel the progression curve is utterly broken. It doesn't feel like a natural levelling progression or said better, smooth XP curve. That's what is stressing me out is, you can complete most mapped out events before even reaching 20% of the level set for that area - The rest is dynamic events that differ so wildly in speed of completion, fun and sometimes they just start when you are in the middle of something else, then when you finally want to do it you need to sit around waiting for it.
I hate that feeling of getting 2 bars in a split second and then 40 minutes can pass where you can the most scraped, pitiful XP that is barely worth your time. I furiously look over the map again and again, and again to find what next even I can run to that'll give me the next pitiful amount of XP and then ALL OF A SUDDEN you find a dynamic event and sometimes, only sometimes it's a good event that will earn you decent XP. Others it's about running around the same quarry for 20-30 minutes seeing a super slow progression bar because it only really moves significantly when you kill, pick up, drop something off ... Not the other players.
And it's also just the areas just doesn't seem to hold enough XP as their level range implies. Believe the step is 15-25 where the entrance areas start off low and as you progress is gets higher. I can barely get 4 levels in the entire zone, let alone 10 before I need to visit other starting zones, and scrounge around the world for more XP. I hate that stressful feeling of having to area jump constantly ... It all feels like vanilla WoW right now.
Don't get me wrong, despite what I said out of frustration, I like the system at heart but right now the execution is frustrating, slow and wildly inconsistent. You don't have that "Yeah, I'll make some progress today, enjoy the game and get to level 25!" more like "Shit, can I even get to 20?"
But I'm enjoying the other big part of the game, PvP and WvWvW is both fun and can yield good XP. ( 3 levels in the last 2 hours, +- )