Lennox, Trane, and Carrier are the big 3 for residential equipment. I worked for Carrier as a commercial sales engineer for 15 years.
I now work for Mitsubishi Electric on the commercial side. The technology of our residential and commercial product line is incredible. We can vary the flow of the refrigerant thru the compressor as well as vary the fan speed on the indoor and outdoor units.
You made a good choice with Trane. Typically, the 3 brands that I mentioned have to be the primary brand of the dealer so they aren't going anywhere. You can see other brands, Bryant, ICP, etc jump around.