Hearthpwn

Puzzle labs are fun, but the most complicated ones also have an "artificial" feeling with them, caused by the presence of made-up cards and a nearly impossible situation in a real game.

That steals a good chunk of their value and satisfaction, imo. 

On the other hand, Dungeons are incredibly dependant on RNG, much more than PvP, and sometimes (too often) a whole Run is compromised by the lack of a particular key loot and/or the right draw for you or the boss to hard snowball the game.

For both, cardback reward is kinda lackluster, but i understand it is hard to give a decent reward without inflating the economy of the game. I also understand the main reward of PvE is or should be a relaxed playtime.

No they are good and diverse ofcourse they could be more challenging but heartstone is not that challenging

Nope, they’re equally as good. Tons of fun!