I own an HVAC business. Most of these prior post are not at all correct. Trane is not what it used to be and Goodman is not made very well. That small of a SEER2 rating difference is not enough to justify $4k difference, unless it is a much better model (which would have better parts, etc). Goodman has a lot of Evaporator coil issues and TXV issues. Trane/American Standard has their issues as well as most of them are electronically controlled expansion valves now. It’s just my opinion, but I like the Carrier/ICP line (TempStar, Heil or Carrier). The most important part is the installation though. That is usually what determines the longevity of an AC system. Be sure to ask questions that make them explain why their service is better than the others. Are your current duct plenums compatible for the new larger Air Handlers? Are they replacing the line set? Are they installing any float switches for overflow protection in the emergency drain pan or drain line in the attic? New pads for the condenser’s? Thermostat options (you can get WiFi thermostats that send alerts to your phone if there is an issue with the system and control it from your phone). This is pretty handy, especially if you are away from home on a 95 degree day and your capacitor goes out! What is their warranty for installation, I am not talking about manufacturer warranty here. I am talking about their warranty on the install. What time frame for the work to be completed? The new refrigerant that someone posted above is coming. But, parts and refrigerant for the R-410A systems, including complete outdoor units will still be available for a long time. And the price of the refrigerant has not gone up. The new systems are going to require a leak detection system on the evaporator coil. They are also expected to be 30 to 40 percent higher. Plus HVAC businesses are going to have to buy new compatible equipment/tools and training. So that will drive costs up too. So basically, go with the company that you trust the most and with their (within reason) recommendation. All manufacturers can have issues, it is the service after the sale that matters, as well as how much pride they take into their work during the installation.