Think cockatrice that trades ergonomics for a rules engine. Much easier to play when the game just 'works'. It even has loop detection for when you go infinite with triggers.
One thing to note is the community run servers are plagued with performance hitches at peak time. If you play regularly on xmage with friends, I'd recommend making an image on your preferred VPS provider and spinning up an instance when y'all want to play.
I do kind of like the manual aspect of cockatrice instead of the automated experience of arena. It feels more like an actual sit-down game IRL. But there are certainly cons, folks frequently miss triggers or debate rules. Still that's magic.
I poked around xmage and found it rather difficult. Cockatrice definitely has a learning curve too, but my first impression did not bode well.
Me and my friends have found that the most fun is to play using https://github.com/dr4fters/dr4ft (dr4ft.info, currently down, mirror here: https://beta-dr4ft.herokuapp.com/#) - we do a draft, then do a best of 3 rounds with the decks that we make. It makes deck-building a core part of the game, and it's always a completely new game. Brilliant fun.
but imho it's more fun to play with either cards you own or with a reasonable limit, because mtg is better with some kind of a social contract in force.
I play very infrequently, so it is fun to say "let's play legacy, pick something random from a legacy top decks list". Gets boring pretty quickly, but I'm burnt out on MtG for awhile by that point anyway :)
I think this contract is usually just the set of rules for deck construction, which is usually just a format. It's not really a problem if one player's preferred modern deck costs $200 and another's costs $2000 when neither of them had to pay for the cards and both of them had the option to play whatever modern deck they liked.
That's definitely a thing. I usually try to avoid games where trying to win is frowned upon in favor of games that are enjoyable when everyone tries to win.
Generally speaking, in Magic, people try to win, but you're not going to be sinking hundreds of dollars into cards when you're just getting into the game and playing against other newbies, making it a self-regulating thing - you spend more money as you need to spend more money.
You're replying to a thread that begins with "Even if you don't own the cards and you're playing with proxies or on cockatrice or whatever, you should still use an additional deck construction rule that places an upper bound on the physical version of the deck."
Works for seasoned players. For myself and most people I play with, we're reading the cards most of the time. Try fitting Shahrazad's text on a card with sharpie :)