When does this game become difficult

[Keydah]

There is a dungeon difficulty spike when you reach level 32 - Brayflox's Longstop. This is when you'll really have to start paying attention to mechanics or you can't get through the dungeon. My boyfriend and I have failed it as tank + heal, dps + dps, heal + dps because one or both of the other people weren't on top of their game. However, the mechanics are easy to get if you have a brain, and you don't have to be reacting on the fly like Titan (I don't remember the normal mode, but the 50 hard mode is really fun)

For the most part, the "whoa omg wtf" mechanics are saved for endgame. The first time you'll see a super crazy fun mechanics filled fight is the second story dungeon of 50, Praetorium...but Praetorium is nothing now if you get any overgeared players. Until then, the dungeons are pretty fun but easy to master between 32 and 50.

[Avery28]

There is a dungeon difficulty spike when you reach level 32 - Brayflox's Longstop.

Pretty much this. You will notice this spike especially as a tank or healer. From that dungeon on stuff starts to hit a lot harder, and you'll get to fairly important mechanics (Doom for example).
The next big spike you'll see will probably be post-50 with Extreme Primals. Most people are overgeared for Titan HM which was a pain at release.

I'd say stick with it. I'm also leveling Lancer/Dragoon right now and it got more fun as I leveled up.

[AzraelX]

omg that Doom... theo ther dps kept dieing at that part....u really have seconds to stay alive...I still the healer rez him twice and the tank once. I actually had to use a LB to finish that boss off