I have. Tyrantus, Open the Waygate (Mage Quest), Pyros(Golden), The Lost Kaleidosaur (Paladin Quest), Sunkeeper Tarim, Fire Plume's Heart (Warrior Quest), Ozruk.
I have 7640 dust, which is enough for four legendaries. I'll be able to get 5 with just a bit more dust.
The ones I really want are the warlock ones, so I can play the discard deck. I also want to play the Priest Deathrattle deck which requires the quest, but also the neutral legendary.
For now I'm not spending. I'm going to wait and see what decks end up being strong and popular.
My feelings after only one night of play is still that the Rogue is the most cancerous non-interactive evil deck, but probably has ways to beat it. The Paladin is still weak, but I have to build a better deck around it.
The Mage is really strong, and I saw the most success with it. Though I might just be seeing more mage wins because I am better at mage than other classes. Also, I was losing to people who have polished decks and strategies no matter what I played, so maybe it's still not good enough?
My mage deck still needs to have more card draw and also anti-aggro tech so it can get to the late game and actually setup the win condition with the extra turn. I lose games to aggro because I couldn't contest relatively crappy boards. I also lost games because I didn't have the arcane giants to go with the completed quest card for the actual win. I think the next thing I'm going to try is elementals. Just playing elementals every turn to activate the synergies and just gain tempo and win boringly. I got the golden bird guy and Ozruk, so I might as well.
I thought Ozruk is bad, and he kinda is because any hard removal, and that's it. However, if your opponent doesn't have hard removal, he is ridiculous. I faced one that was a 25 health taunt. I didn't draw my sheep, so it was GG.