Magic Arena is clearly meant to go the Hearthstone route as far as ease of play. Of course Magic is a much more complex game. So I'm saying nothing unique when I feel that Arena has a bit of a ways to go to be smoother and smarter.
The "auto-tapping" of lands is nice, but sometime it's dumb. if I have a Jade Bearer and Jade Guardian in hand with two Forests and three Islands, I am going to play the Guardian first, and yet it decided to tap both of my forests. I have only one playable card left in my hand it did not think to leave up the mana to play it.
Other oddities are it asking me to "choose target opponent" with Doomfall but not with the Oblivion half of Consign // Oblivion. Okay... Weird, considering that there is only one opponent.
Also, no matter of "holding priority" via holding down control lets me respond to The Scarab God's upkeep trigger with snagging something out of the graveyard. That is valuable damage lost over time.
The rate of collection feels slow. Each win after four in a day results in just commons instead of gold and a card, so 350 gold plus whatever daily quest you got is the limit. With packs costing 1000 gold, I didn't get to open a pack today as I am sitting at 950 gold. Or wait, did I get a pack for my first win? Honestly, it's hard to remember. The point is that I sure don't feel like I am acquiring cards at a heavy rate, although you do seem to keep getting commons for wins (My max ws 16 in one day.) which I assume begins filling the Vault once you have a big collection.
But it feels fairly good to play, and going back to Magic Online to finish a league after messing around with Arena, Magic Online sure felt like going back to an older way of working.
So I have hope for Arena. As I doubt Modern and Legacy will be there, I am tempted to sell out of Standard on Magic Online and just keep playing paper Standard and whatever you call what Arena currently offers. (No Kaladesh makes for weirder decks, to be sure.) Then I can get my digital Modern and Legacy fix on Magic Online, where the cards will probably hold their cash value longer than Standard would anyway.
I mean, I saw Heart of Kiran for ¥400 the other day. It was ¥4000 last year at some point.