The only zapdos player around here currently is lil' Kevin , (Kevin-) and i've seen the consistancy of zapdos. Zapdos works excellent, it has good odds of getting what it needs out, and it doesn't need much so the rest of the deck can be open to any other original spins you want to put on it.
At the riverside CC, he played it with bellossom, which was an interesting tech, and it seemed to have worked because he won 11-14. He's changed the deck since then though, now running manectric with it.
The 2 downfalls of Zappy: Bad start, (As in, no energies) simply outsped. I've done both of which with my current deck.
At the league mini-tourney recently, i got set up fast and kev had no energies so i won turn 3.
On apprentice, i took out a voltorb turn 1 with rare candy, psy shadow, boost.
But this won't always happen, and that's where zappy wins. However, regardless of how much it can hold on to a game, it still relys on super scoop up almost all the time, and if you don't get that, then you're left hanging.
All in all, zappy's a great deck, worth running, but still isn't that big, and not invincible.
Maybe i'm coming off as some raving lunatic, but i'm up too late to be thinking straight anyway. *shrug*