I have just started using Squish a week ago, so far so good. The tools looks good! It has many versions and I think it's the only one that can claim one script will run on Windows, Linux and Mac which is object based instead of Graphical based.
I actually picked it up because it's the only one that can claim support for QT which is what the application I'm working on is developed in.
We're actually working on a project that is also being developed in QT. We've been looking at Squish/QT to see what our options are. We're still contemplating this or to do some work creating an API to use our existing tool to handle the automation.
"Tests created with Squish/Web are browser- and platform-independent. This means a test created e.g. on Windows in Internet Explorer will run without any changes e.g. in Firefox on Linux and Safari on Mac OS X."