I'm pretty happy with the unit testing framework too. I've got tests for all the basic things you can do with signals, and the stress test to check whether the whole system chokes if you keep connecting and disconnecting slots from a signal over and over again. If other bugs crop up I'll add more tests in, but I think it's solid enough for me to move on.
The only minor annoyance is that I haven't specifically written test cases for all the possible types of Signals I have, mostly because it's a royal pain to do so. The problem is that I need a different Signal class for each number of arguments in the functions used as the slots. The code is almost identical, but the minor edits you need to make are annoying to do. I'm almost certain that if it works for one it should work for them all, but if not I'll have to buckle down and write the full set of test cases for all of them.