Has anyone tried to port some of their scripts from any of the 'Big 3' commercial automated tools to an open source tool ?

If so, I'm wondering if you might share your experiences - especially in terms of what the technical obstacles were, and if the overall lack of support caused any issues. (I personally find Mercury support indispensible at times - I've had some nasty Access violations deep in the hooking mechanism on ActiveX objects that I could have never solved on my own - Mercury did supply a workaround).

While Linux seems to be the most successful open source product out there (and I realize it's really not as 'open' as it used to be), I can't imagine any open source tool replacing what QTP does for me - especially in terms of the object repository.