A Guild Wars 2 Dilemma

With my copy of the Guild Wars 2 collector's edition pre-purchased and my beta key in hand, I now face a tough decision. This is really a first-world-problem kind of tough decision, but still. I may need some help deciding between a few options. Of course, whatever I end up doing, I'll write about it here.

I put well over 2,000 hours into the first Guild Wars, and about 99% of that was as an Elementalist. It's my favourite class by far. So, knowing that I have access to the next Guild Wars 2 beta, I face a tough decision:

Do I play an Elementalist to see the changes made, and to get a feel for the game using a class I know I'll enjoy?

Or do I go for a new experience with something that wasn't in the first Guild Wars (Engineer, Guardian, Thief) or something that's changed drastically (mesmer)?

And after I resolve that problem, I'll then have to decide whether I want to play a mix of all game modes, or one (or a few) of PvE, structured PvP, world vs world.

I also don't know if I'll want to just get a feel for the game and enjoy it, or spend my time thoroughly examining every little detail.

The only thing I know for sure is that I'll want to spend some time in Lion's Arch, since that's a new area being opened up that wasn't in previous betas, and is an update of one of the biggest and most popular cities from the first game.

Any of you readers have an opinion on what I should cover? Leave any suggestions or requests you might have in the comments!