The grind is about 400 hours to get every card, and there's quite a lot of them at the moment, even though not all paper cards were implemented.
It works well as a game you fire up for an hour or three, play a few games, do the daily quests, buy a booster or two, call it a day.
Two Headed Giant works quite ok with a friend (random people are a nono), I actually played it the other day and there weren't any connection issues for a change.
It also lets you grind in a bit more convenient fashion.
Also, you can't really clock these 400 hours in one go, cause you're limited to earning 300 shekels from victories per day.
However, the game is terribly underdeveloped. The tutorials haven't been working properly since forever (dunno, I picked it up a year ago and they were still fucked in a way you describe),
not all cards are implemented, simply because it would probably take too much work.
The AI got some rework, and has a few tricks up its sleeve like noticing man-lands or bounding own creatures back to hand to save them. It's still clueless when it comes to using vehicles though and makes dubious decisions with some cards
(e.g. when choosing what to save for cataclysmic gearhulk).
Biggest downer for me is that one a new expansion is released, all older AI decks are shelved and you're stuck with it playing the same shit from the most recent expansion over and over again.
Anyways, the game will probably get the axe once WotC releases the newly announced Magic Next, so I'm not sure if I'd recommend it. I had my share of fun with it (some parts of the Story Mode are quite well done),
but I'm honestly only sticking around to get the last steam achievement for completion's sake.