Dungeon soloing

I'm pretty new player (currently around 180CP) and have hard time choosing the main atm. Which of the classes is best suited at dungeons (Inc vet) and arenas soloing?

I have magsorc, magblade and magplar capped atm.

It seems that community usually recommended spec for soloing, is that still the case with CP changes and upcoming exoanion?

What's the downside of going magblade?

I'm open to other classes if those are better.