I hated 52 when it first came out. Too many z-listers, cruddy art, all in all, not impressed. Plus it irked me that they didn't seem to use the full potential of the weekly story device - ie, sometimes only using one or two days per issue.
But now I'm re-reading it all in the trades and I am absolutely loving it. Maybe that's the best way to read it.
Perhaps part of the reason for this is that Countdown is so crap. Really bad art, a very lightweight story, minus-Z list characters, and a story concerned with tying in too much with current events in the DCU. Plus I miss the little next issue preview panels. 52 is such a dense, engaging read, and, sadly, you can't compare Countdown to it.
Maybe 52 is just a one-off classic... I hope not.