I really like the 'detail' output of Test::TAP::HTMLMatrix, and agree with Kent about how useful such a summary can be, not only for managers but for developers too - it can make tracking down test errors easier because you only need to scan colors rather than lots of text.
But I've got a couple of gripes:
1. it doesn't tell me *why* my tests broke - no debug info, nothing. Just that it was not ok.
2. debug output that goes to stderr still goes to stderr. perhaps this is a T::H::Straps limitation?
3. it's not as customizeable as I'd like. For example, I find it annoying to have to subclass to redefine the css_uri.
4. It's built on Test::Harness::Straps, which is deprecated.
Hence the 3 overall - it's a useful module, but it could be more useful.
I really like the output this produces, especially all the extras that go into it with mouseovers and everything. It's really pretty awesome. It's nice to have a web page you can point your managers to for measurable progress.