I have no problem with the rate of updates.
Two things I would like to see, though, one easy to implement, and the other potentially controversial and probably impossible to do satisfactorily.
1) Add a "highest position achieved" counter to the Arena. So if you put up a deck you can know the highest it's reached in the rankings without having to have been actually logged on at the point at which it achieved it.
2) Make the Arena decks more diverse. I'm not really sure how it'd be possible to eliminate rainbows from the Arena, but even if you did you'd just have endless copies of identical non-rainbow decks. What I do is take the card that I'm given, roll an online 12-sided die and then make a deck which utilises the card and the element rolled (1 = entropy, 2 = death, etc.). Perhaps, along those lines, keep the Oracle card mandatory in the deck, but also have a random, fixed Mark that has to be used.
Another idea would be to have wins and losses be the only factor determining ranking, and determining nothing else. Thumbs ups, on the other hand, reward you with
, and thumbs downs take it away (although you can't drop below zero). That way people would want to make decks which won, because they'd stay in the top 500 longer, but would also want to make decks which were interesting to play against, because that's the only way they'd win
. Or, perhaps, for slightly different scoring, one thumbs up earns you 1
, 2 earns you 2, 3 earns you 4, 4 earns you 8*, etc. and a thumbs down resets your counter back to 0, so your next thumbs up only gets you a 1 again.
*Or, 10, 20, 40, 80, perhaps.
As I say, potentially controversial and almost certainly impossible to implement satisfactorily, but it would make playing the Arena much more fun.