I think it's generally sort of an issue that some treasures are more powerful than others, given how big an impact they have especially on your first few matches. And with every class only having one hero power and one bonus card, you are already pushed you into a specific playstyle and would find some treasures better by default. That said, it also depends on the class which treasures you can make good use of.
But remember that it's not even in public beta yet. I think we can expect a lot of changes and new additions over the next few weeks and months, just like with Battlegrounds. Some treasures might get upgraded, downgraded or removed, some hero powers might get tweaked, or some pools for buckets changed.
Robes are powerful but other combos are pretty crazy too. I just played a game against a hunter who had the 1/2 cost minions are poisonous and the deathrattle minions have reborn treasures. He coined a Haunted Creeper on turn one and basically locked out the board for the rest of the game with that one play.
There will be balance changes so I'm not panicking about it but it does feel like you come up against some opponents and have close to zero chance because they high-rolled better treasures than you.
I’m a serious hater of double casts on your first spell, blessing of authority for +16 +16 four separate times.... not sure what to do about that. I’m sure it’ll be a long balancing nightmare over the next several months. But maybe when more treasures and HP are available it’ll be a little easier. I still find the mode pretty fun. But obviously blizz isn’t super great about hitting the balance on first release of anything.
The robes are very common when you get to higher win totals, but the solution might be as simple as making them round up instead of down. There are a lot of powerful passives, and the fact that they feel broken is part of the appeal, robes just seem a little bit out of line with the others.