Actually, I had the tech who installed the heat pump come out first and he found the leak at a solder joint/braze point at one of the bends in the coil. The company who installed the air handled actually checked it too and found the same thing and they did the warranty install. After a week, the system stopped cooling so I called them back. He suggested a full leak test after he found the freon to be low, but while he was there he checked the connection that they soldered when they installed the unit with his leak tester. He noticed a leak at the plastic cap over the schrader valve. I think he then tried to remove the valve so he could replace it but would not come out (I'm not 100% sure on that), but he eventually put a metal cap on it with some type of sealant. The unit then worked great until now.
As far as Goodman being up on their warranties, it has not happened with me... My air handler was installed in 2005 but had a November 2003 manufacturing serial number. Even with a copy of the "actual" credit card charge and bill/invoice from the dealer, they refused to warrant the repair because they said there was no way a November 2003 unit could have been installed a year and 3 months after it was manufactured! I had to deal directly with Consumer Affairs and the Warranty Department at the Goodman facility in Houston.
But my question now is...Should I pay the $1080 quoted to replace the compressor under warranty or try to find the cash to replace the entire system maybe starting at $3500? After I pay the replacement costs, essentially the entire system will be out of warranty!