The company I work for bought a new package last year after using the previous package for about 10 years. This time we bought a custom designed network package, so that (in theory) all our network talk stations would sound almost the same.
Here in Melbourne, having the number one station in the market, we worked hard on the re-launch. The package contained about 6 different styles. We mixed versions of every style, for every show. All up, it took us about 4 weeks from when the project first started, throught the New Years Day launch, and mopping up bits for shows that followed during that week. All up I think there was about 3000 bits that needed re-doing.
Listener reaction was fantastic. I remember taking a call from a friend in another market, asking me what the hell happened? He, was a fan of the idear of gradual introduction, which I can't understand.
Anyway, 12 months, and one frequency change (in which about 1500 bits had to change again) down the track, we are still number 1. The thing that had our production manager scratching his head was, what other stations in our network were doing. They all went for the gradual approach, and 12 months later, from what I have heard still haven't used half the stuff in the package.