As you get most of your basic skills early on and you're fully unlocked at lvl30 (slots not all the skills), I feel that 50 extra levels is a bit redundant to get to max level.
Personally I didn't see the need to have 50 more levels as there isn't too much more to learn between lvl30 and 80 what world events and heart quests are concerned. To me it got pretty stale as there's nothing new compared to lvl 1-30. The occasional extra support skill you unlock doesn't keep me excited for an extra X levels.
The thing is that once you have one lvl80 levelling another character feels really grindy.
The thing is that play style in dungeons (I think I have done 80% of the possible dungeon "paths" at least once and it's my main in-game activity, both with guildies as pugs) is totally different from what you're used to in the levelling areas, it almost feels like a different game. Suddenly there's lethal red circles carpets and 1-shot bosses that can jump you and being downed is something that's just going to happen because of that. You basically have to learn to play your class all over again, the skillset that was perfect for levelling appears to be absolutely unfit for dungeon play.
Which is another reason I think 80 levels is quite overdone. But once you're used to it, it's usually not very hard or challenging, you just follow the experienced players and you're done before you know it. There's also a few harder ones but as you may expect, there's a few easy ones that people do a lot as they're both easy and profitable.
I guess you'd like GW2 well enough, it's not a bad game.