Arena is a perfect electronic conversion of the standard tabletop version of M:TG. This is both good and bad.
The good is that you can sit down and play a game at any time. Just a couple of clicks and you're playing against someone with your favorite decks.
The bad is that you can sit down and play a game at any time. just a couple of clicks and you're playing against someone with the most popular decks and the least imagination.