I updated my two Debian sid systems to insserv and dependency based booting today. The update was on hold for so long (over a year!) that it was growing a fungus. ^_^
After the positive experience with the Debian squeeze upgrade, and the fact that some packages are now depending on insserv (shudder), I decided that not updating was likely to become troublesome in the near future. The one thing that you should never do on Linux, is fight against the package dependencies, even if you don't agree with them. Thither lies dependency hell. Trust me, you have better things to do.
Hopefully, this will be the final word on insserv. Unless it breaks, of course. ^_^