I think the best part about playing Eternal, as a hearthstone player, is that the two games are different enough that I like playing both. I've been kinda looking for this in a DCG and a lot of the close calls I played recently (shadowverse, duelyst, and elder scrolls legends) are too similar to hearthstone. Those other card games I ended up moving on from because they don't provide a compelling reason to play over hearthstone, while this one does because it's very different.
This is where i'm at, though with duelyst it was more the artstyle rather than it not being different enough.
Having to start a collection from 0 is really the big hurdle. I have so many cards in hearthstone i can build any deck i want. Will be hard to go back from that.