Yes I love the xenosaga trilogy, as well as the PS1 predecessor xenogears. Storyline is pretty complicated and it takes a couple of time through to get what is exactly going on. Love the music and graphics, but gameplay and mechanics of the xenosaga series makes it a little tough to keep playing when you've been doing the same thing over and over again. I would recommend this game to anyone who loves a good RPG with a good plot and graphics.
As for Xenocard, it is an in-game card game (just like FF8 and 9)and when u win championships you get a good chance to get rare cards. I would check around the internet (I go to Gamefaqs.com) for card strategy and locations. Good game, but tough since you can only make a small deck with a limited number of cards.