1. No online CO-OP
Alright, I concede this point. Everyone was disapointed that the co-op mode was local only and not Internet-enabled.
2. No Text chat
The Steam community is available in all Steam games and includes text chat. As Duels of the Planeswalkers (DotP) is built on Steamworks, it is easy enough to start up a chat with another player based on their Steam username.
3. Game is currently unplayable for several users, especially some users with ATI video cards. <-- upgrade your video card drivers and try the demo first.
This can be said about every PC game. PC is a hostile and varied platform to play on. So far, I have had no issues and I know no one who has had any (out of three friends playing).
4. No deck building <-- I knew this going in but still its a negative in my book and even more so now that we have discovered reasons # 1 - 3.
If the original poster knew this, then they are dumb for including it. If they expected differently, they are playing the wrong game. MtG: Online is over here. And for clarity's sake, there is minor customization as additional cards can be unlocked for each deck and added or removed before each game.
5. Music / Sound. its horrible and very annoying.
It can be disabled. Plus, its a fucking card game, what was expected for sound? Turn the damn radio on.
6. the game auto taps your land cards for you.
Finally, a second point I can agree on. This is annoying and borderline game-breaking for multi-color decks.
7. You cant mute the other player online. <-- which sucks because some times you just dont want to know what they are doing with their other hand.
OK, I'll give in on this one as well, but I maintain there is still the ability to turn off the sound on your PC.
Conclusion
Buy the game, but don't expect a hardcore experience. It's fun, casual MtG.