TERRIBLE SERIVCEI
I had a carrier Comfort series air conditioner installed in 2009. In 2011, it was no longer cooling and so I called for service. They simply refilled the leaking Puron, without diagnosing the problem and told me that the problem was the cold weather which caused the leak. And because it was not a "mechanical problem", it was not under warranty and charged me for the repair.
This summer (2012), again, our air conditioner is not cooling. This year, they don't even have the decency to return any of my phone calls requesting service (I guess they are too busy scamming others).
They sound very nice on the phone and are very nice when installing product. If you go with them, just pray that nothing breaks down because their "warranty" is only worth as much as their "word" (i.e. totally useless)