The avatars would have been a good way to balance out some of the issues with the current masters. Why is avatar Seamus any more broken than a Dreamer boom-a-rang across the board or Pandora's 12 inch bubble of go on hit yourself and take a wound. I like that the masters can transform in game, its a nice idea but I would still have liked the option to start as an Avatar.
As for the argument "why would you bother with the standard master if you could start as the Avatar" surely that highlights the various power levels of the base masters.
Again just my opinion. The Avatars in there current format bring something different to the game, but I for one would still like to build a crew around an Avatar and start with it on the board instead of spending two activations casting a particular spell or action so I can Avatar up in turn three.