I've been working on a "new" version of SUnitToo(ls). With the 4xx browser series, we rationalized the the tab model some, and made doing what the SUnit code tools were doing (wrapping around the source tool like a parasite) more difficult. I spent some time a while back talking to a couple of other SUnitToo users who liked using the tools in the browser, and eventually, I've finally gotten around to try and realize those. Those consulted are free to disavow themselves from the results if they wish. :)
The screencast below shows some of the new tool in action. It doesn't show it all, things that haven't changed really, things like "Step Into", or the way the debugger just pops up when you're in "Debug It" mode with the failing assertion highlighted. Or the whole swapping between Object and ObjectTest buffers things. Or the way you can quickly convert a legacy SUnit TestCase into an SUnitToo one, do your work, and then convert back.
Give it a go. You can use it with the 4xx browser (load Tools-RefactoringBrowser bundle into an image with no open browsers) from the Open Repository, then load the "RB4xx" variants of SUnitToo and SUnitToo(ls) from the same repository.