This is a follow-up to my original post.
The HVAC guys are down in my basement right now pulling out my old system and installing the new one. When they pulled the cover off the unit, the technician noticed right away that the previous installer rigged the evaporator coil with a side intake.
The way he had it going, only one half of the coil ever saw any use. This is evident by the amount of dust that collected on one side of the coil. That means my compressor had to work twice as hard to heat and cool my home over the last 10 years which is probably why it failed when it did. Frankly, I'm surprised it even lasted that long.
This experience reinforces what Bubba said about finding the right guys for the job. I can only wonder how many dollars the previous home owner wasted heating and cooling this place because the HVAC guys that put this system in either weren't qualified to do their jobs or just didn't care.
Thanks everyone for all of your input.