They (signoffs) play a very significant role in the project lifecycle and add tremendous value and leads to an overall positive outcome to your project. But like everything else, there is a time and a place to use signoffs. Using a signoff should not cause and be looked at as an unnecessary burden.
I have seen that using signoffs during a software implementation that is using a waterfall methodology is most appropriate. There are distinct phases, each phase is broken out into more granular tasks and everyone is aware going into the project on what happens next.