I haven't had a chance to think deeply about ST possibilities yet, but I agree with those saying the Harmony change seems a bit excessive, when Harmony archetype if played with any other leader than Mystic Echo is not that crazy.
Mystic Echo should just have been changed to something else that supports a special/spell archetype - eg Sages/Farseers/Johnny/Sarah/Gord... that type of deck is not great and could benefit from Mystic Echo eg "boost a unit by X whenever a you play a special card", Y charges, or something like this that works around special cards but not doubling their effects...
But anyway, what's done is done - I'm wondering if Symbiosis can be used to support Harmony eg it essentially does a similar process in terms of gaining points for other units with the symbiosis, just happens to spread these points onto a separate token instead of boosting the same card as Harmony does. May be room to experiment with some cross overs.
On a separate note I like the few things thrown to Handbuff. Sure Filavandrel (Invigorate) still could do with a buff/change, but there might be some interesting possibilities now.
And I like the increased number of treants, especially low provision, and more nature cards - will play around with Call of Harmony and see what can be done here now (I still love the Etriel+Muirlega CoH combo too much).
And FINALLY - Saskia gets a change!! Been so sad to not use this card for so long, though not sure if the change is worse or better... might see what can be done with it now. Just please give back the old awesome premium Saskia with better fire effects.