I don't know what others have said, but I will tell you how it is here in the Northwest.
For starters, yes.
I will get a lot of flak for this but I don't care.
If you are playing for fun you won't see it so much, if you are playing competitive, or are a meta gamer like we've been accused of, you will see it all the time.
Again, I am ready for negativity but Hamelin is broken, there are a lot of pointless arguments on here when he came out and even though we have stopped playing because of all the silliness, no real change has been given.
The rest of them are very balanced because like most Book 2 masters, they require some finesse to do well. The main reason why masters such as Hamelin and LCB are overpowered is because playing them is really simple.
If you had two people of equal skill level, even at this point, it would be rather difficult to beat one of them...Hamelin more-so than any of the others.
Also, many of the models in the second book were meant for their respective new masters, so if you want to play an old master, you are stuck with old models. Yes, Book 3 is out but I have yet to buy it...but at this point, I don't know if I will.
I leave you with that. I apologize if it seems negative but I have been let down somewhat over my course of playing.
I started out bright-eyed and cheery about this new shining gem only to be given a lot of misconceptions and really silly community members. Not all of them are like that though...like Karn, he's cool...and Nilus.