Interesting. I am adding Grand Aire to my site in a couple weeks. I have discovered that Grand Aire is different product in different parts of the country. In the north and east, it is a Nordyne product. I am pulling mine out of the south and it is an ICP products.
I think it is like all the rest, if you are promoting yourself and not the brand, and you are a competent installer, it's all good given the two manufacturers.
I chose the Grand Aire (ICP) product because they have a 13/14 SEER builder grade product that is well built and will allow me to go head to head with Goodman in my market. I still can't match the fairy tale warranty, but that is just marketing.