After reading 52, Countdown to Final Crisis is sadly disappointing. Luckily I knew that going in, so I was able to adjust my expectations enough to at least partly enjoy some of it.
Countdown tries to do some of the things that 52 was very successful at. It was published weekly, using a stable of writers and artists presumably working under the same plan to tell multiple storylines with mostly minor and semi-forgotten DC characters. But 52 was much more successful, sometimes wildly so. Partly because of the storylines themselves. I honestly cringe every time I turn a page and see Jimmy Olsen staring back at me. Please, no. Most of the other storylines are lackluster at best. The only one that I feel any real attachment to at this point is the Piper and Trickster storyline, because I think I kind of love those idiots. Then there's the less-than-inspiring art, where the style and even the quality varies far too much. It's serviceable, but that's about it.
Countdown isn't bad. At least not yet. It just isn't terribly good.