This is one of the best developer plugins I've used. It will replace the HTTP logging in Core Control and the query and hook monitoring in Debug Bar (and associated plugins).
When I am looking at why a site is slow, I look for these things:
* What external HTTP calls are being made?
* What SQL queries are being run?
* ... by which plugin/core/theme code?
* ... how long do they take?
* What is hooked?
This plugin tells you all of that information in one click. Absolutely outstanding job. 5/5 stars and I look forward to the continued development of this project.