So, what is the problem? The 4l80s are very solid as have been the 6l80s. The 4l60s lasted if you kept the heat off of them. The ones with small or non-existent coolers had more issues.
I have been leary of these new 6, 8, and 10 speed transmissions. It just seems like a lot more heat to deal with. Is that the problem or the components?
For the record my wife's 6l65 seems to be fine too.