I haven't. I thought I'd like to do that, but of course I don't have one that's good enough handy (i.e. the cheaper AT cart that I first upgraded would give me sibilance and IGD when it was operating normally). Making a purchase for this reason only would be a real drag, but I'm kinda with you here -- I don't want to end up buying a totally different cart that's more expensive (because let's face it, nothing cheaper is going to perform like the PTG does at its best) and end up destroying that one too. I'm going to head to another dealer on Saturday, though he's not a VPI guy, and see whether he wants to take on this challenge with me.