the cards don't add replayability as much as they add randomness (not overpowering randomness, but they do cripple a lot of the "figure out what the other people need" part of the game- which is the primary form of interaction. any time you could be blocked, you can almost always fix your bad play with the cards). my rating drops 2 points when playing with the cards. the "family game" is the better way to play for gamers.
and when playing it without cards, this is one of my favorites. Pushes the boundaries of what you can reasonably parse while still keeping track of your opponents (sitting it right along the edge of challenge:skill for me, making it highly enjoyable), with heavy interaction if you actually understand the game.
the only random element is the initial setup, which is viewable by all- excellent mix of strategy and tactics, direct and indirect interaction, along with interesting and constant decisions, all in 45 minutes to an hour. This hits all the right buttons for me, and makes me want to play it MORE every time I play it.
people often only state the things they perceive as having been "done wrong" in Magic. unfortunately, most CCG's missed the important things that were done right.
people complain that the cards have gotten too powerful- and i say you build a deck with what you believe is the most overpowered recent set, let me build a deck with just the original set, moxes, black lotus, dual lands, swords to plowshares, timewalk, etc.
If you want to do the most recent base set along with its 2 expansions, i'm fine mixing the original set in with Arabian Nights and Antiquities. Khird Apes, Serendib Efreet, Mishra's Factories and Workshops... it will be fun.
people say that the game is too expensive. if you're good enough at the game, the only cost is tournament fees- you win more than enough product to keep you playing competitively.
What really happens is that people's perceptions change- and they are inaccurate... either misinformed or tainted with nostalgia.