The main difference is that Theseus allows you to better understand how the code was executed in terms of number of calls for each function and how the calls were chained together, all of this while running the page in Chrome or Node JS. You can click on any call of a function to inspect the arguments and return value.
Theseus can be integrated with Brackets. You can install it from the extension manager.
Here are some screenshots:
Tom Lieber (an MIT student) has a blogpost/video to introduce the project here. Let us know what you think!