I really can't add too much to the previous mentions... I'll mostly support the pacing problems and the overly cynical tone. Though the pacing is still decent in the early stories I say in 4 and 5 it's... it's like he just tries to drag it out to make more money? I don't know...
And the tone... I guess it became apparent from the beginning but sometimes it's really grating. But I'll say this is mostly a matter of personal preference.

Then again, I really like the characters and I'm always way too curious how a story ends.