I like Naruto, but I agree that Shippuuden is pretty boring. I'm not sure why as they don't have many fillers... but yeah, I stopped watching around episode 50. Maybe it is just because they are doing the episodes like Dragonball Z where they stretch one chapter of the manga into one episode rather than 2 like what is normally done.
For some reason, I've also been pretty bored with the manga as well, but recently I think it's picked up. (I really enjoyed the last 5 or so chapters) Maybe it's because I shouldn't read them before reading One Piece (because all the time I'm just thinking about wanting to go to read the next cliffhanger in One Piece, as it has been doing one after the other for the past few months, lol)
As for the English dub. It's good, far from horrible. I say no complaining, we don't have invisible guns, stupid puns, or misplaced voices. It's a good dub! Believe it!
Edit, I guess to add one more thing. I like that Sakura is interesting in the second half of the series. I found her a really annoying liability in the first part of the series, and now she seems like one of the more powerful Ninjas in the village. I wouldn't call it character development, because it was such a big jump and we basically missed her change, but she definitely was made more interesting.