Yeah, shadowverse UI was clearly made for mobile and it works there but just a straight port to steam was rather lazy.
I think Eternal is going to be a very solid release. It has a singleplayer campaign free from the start, which serves as a solid tutorial to each of the colors. It has gauntlet, more singleplayer content, that can be done for free to help earn your collection and complete quests. Then it has a singleplayer draft mode. This is in addition to multiplayer draft, ranked ladder and casual. Also, the draft mode is way better than hearthstone's (I haven't actually tried it yet but I've seen kibler drafting) and drafting has the benefit of keeping the cards you draft.
What really works for me is the breadth of the mechanics Eternal manages to achieve without the text being overly-complicated. And how well it has adapted the MTG formula to a digital format. It's not just magic being played digitally, it's a game that has been designed from the ground up to be played that way and the mechanics show it.
For example, permanent stat buffs follow the unit to the grave and if you use a spell to retrieve it (no lol rng, you actually pick the card you want), those stats are still there in your hand and then when you play it again. Same thing for sap. Attachments, on the other hand, are destroyed when the unit leaves the field.
Just a couple other mechanics: target your own cards in hand for buff (example: +1/+1 to a unit or weapon in your hand). Buff the top weapon or minion on your deck with +1/+1. Reduce the cost of the first spell at the top of your deck.
I think players who want a deeper card game than hearthstone or shadowverse (and several others) may fall in love with Eternal. And the f2p model is somehow better than all the above due to gauntlet being free.